Organizing a penetration test

Before we start firing sophisticated and complex attacks with Metasploit, let's understand the various phases of a penetration test and see how to organize a penetration test on a professional scale.

Preinteractions

The very first phase of a penetration test, preinteractions, involves a discussion of the critical factors regarding the conduct of a penetration test on a client's organization, company, institute, or network with the client itself. This phase serves as the connecting line between the penetration tester, the client, and his/her requirements. Preinteractions help a client get enough knowledge on what is to be performed over his or her network/domain or server.

Therefore, the tester will serve here as an educator to the client. The penetration tester also discusses the scope of the test, gathers knowledge on all the domains under the scope of the project, and any special requirements that will be needed while conducting the analysis. The requirements include special privileges, access to critical systems, network or system credentials, and much more. The expected positives of the project should also be the part of the discussion with the client in this phase. As a process, preinteractions discuss some of the following key points:

• Scope: This section reviews the scope of the project and estimates the size of the project. The scope also defines what to include for testing and what to exclude from the test. The tester also discusses IP ranges and domains under the scope and the type of test (black box or white box). In case of a white box test, the tester discusses the kind of access and required credentials as well; the tester also creates, gathers, and maintains questionnaires for administrators. The schedule and duration of the test, whether to include stress testing or not, and payment, are included in the scope. A general scope document provides answers to the following questions:
  • What are the target organization's most significant security concerns?
  • What specific hosts, network address ranges, or applications should be tested?
  • What specific hosts, network address ranges, or applications should explicitly NOT be tested?
  • Are there any third parties that own systems or networks that are in the scope, and which systems do they hold (written permission must have been obtained in advance by the target organization)?
  • Will the test be performed in a live production environment or a test environment?
  • Will the penetration test include the following testing techniques: ping sweep of network ranges, a port scan of target hosts, vulnerability scan of targets, penetration of targets, application-level manipulation, client-side Java/ActiveX reverse engineering, physical penetration attempts, social engineering?
  • Will the penetration test include internal network testing? If so, how will access be obtained?
  • Are client/end user systems included in the scope? If so, how many clients will be leveraged?
  • Is social engineering allowed? If so, how may it be used?
  • Is Denial of Service attacks allowed?
  • Are dangerous checks/exploits allowed?
• Goals: This section discusses various primary and secondary objectives that a penetration test is set to achieve. The common questions related to the goals are as follows:
  • What is the business requirement for this penetration test?
  • Is the test required by a regulatory audit or just a standard procedure?
  • What are the objectives?
    • Map out vulnerabilities
    • Demonstrate that the vulnerabilities exist
    • Test the incident response
    • Actual exploitation of a vulnerability in a network, system, or application
    • All of the above
• Testing terms and definitions: This phase discusses basic terminologies with the client and helps the client in understanding the terms well
• Rules of engagement: This section defines the time of testing, timeline, permissions to attack, and regular meetings to update the status of the ongoing test. The common questions related to rules of engagement are as follows:
  • At what time do you want these tests to be performed?
    • During business hours
    • After business hours
    • Weekend hours
    • During a system maintenance window
  • Will this testing be done in a production environment?
  • If production environments should not be affected, does a similar environment (development or test systems) exist that can be used to conduct the penetration test?
  • Who is the technical point of contact?

For more information on preinteractions, refer to: http://www.pentest-standard.org/index.php/File:Pre-engagement.png.

Intelligence gathering/reconnaissance phase

In the intelligence-gathering stage, you need to gather as much information as possible about the target network. The target network could be a website, an organization, or might be a full-fledged fortune company. The most important aspect is to gather information about the target from social media networks and use Google Hacking (a way to extract sensitive information from Google using specific queries) to find confidential and sensitive information related to the organization to be tested. Footprinting the organization using active and passive attacks can also be an approach.

The intelligence gathering phase is one of the most crucial aspects of penetration testing. Correctly gained knowledge about the target will help the tester to simulate appropriate and exact attacks, rather than trying all possible attack mechanisms; it will also help the tester save a considerable amount of time as well. This phase will consume 40 to 60 percent of the total time of testing, as gaining access to the target depends mainly upon how well the system is footprinted.

A penetration tester must gain adequate knowledge about the target by conducting a variety of scans, looking for open ports, service identification, and choosing which services might be vulnerable and how to make use of them to enter the desired system.

The procedures followed during this phase are required to identify the security policies and mechanisms that are currently deployed on the target infrastructure, and to what extent they can be circumvented.

Let's discuss this using an example. Consider a black box test against a web server where the client wants to perform a network stress test.

Here, we will be testing a server to check what level of bandwidth and resource stress the server can bear or in simple terms, how the server is responding to the Denial of Service (DoS) attack. A DoS attack or a stress test is the name given to the procedure of sending indefinite requests or data to a server to check whether the server can handle and respond to all the requests successfully or crashes causing a DoS. A DoS can also occur if the target service is vulnerable to specially crafted requests or packets. To achieve this, we start our network stress testing tool and launch an attack towards a target website. However, after a few seconds of launching the attack, we see that the server is not responding to our browser and the site does not open. Additionally, a page shows up saying that the website is currently offline. So what does this mean? Did we successfully take out the web server we wanted? Nope! In reality, it is a sign of a protection mechanism set by the server administrator that sensed our malicious intent of taking the server down and hence resulted in the ban of our IP address. Therefore, we must collect correct information and identify various security services at the target before launching an attack.

A better approach is to test the web server from a different IP range. Maybe keeping two to three different virtual private servers for testing is the right approach. Also, I advise you to test all the attack vectors under a virtual environment before launching these attack vectors onto the real targets. Proper validation of the attack vectors is mandatory because if we do not validate the attack vectors before the attack, it may crash the service at the target, which is not favorable at all. Network stress tests should be performed towards the end of the engagement or in a maintenance window. Additionally, it is always helpful to ask the client for whitelisting IP addresses, which are used for testing.

Now, let's look at the second example. Consider a black box test against a Windows 2012 server. While scanning the target server, we find that port 80 and port 8080 are open. On port 80, we see the latest version of Internet Information Services (IIS) running, while on port 8080, we discover that the vulnerable version of the Rejetto HFS Server is running, which is prone to the Remote Code Execution flaw.

However, when we try to exploit this vulnerable version of HFS, the exploit fails. The situation is a typical scenario where the firewall blocks malicious inbound traffic.

In this case, we can simply change our approach to connecting back from the server, which will establish a connection from the target back to our system, rather than us connecting to the server directly. The change may prove to be more successful as firewalls are commonly being configured to inspect ingress traffic rather than egress traffic.

As a process, this phase can be broken down into the following key points:

• Target selection: Selecting the targets to attack, identifying the goals of the attack, and the time of the attack.
• Covert gathering: This involves the collection of data from the physical site, the equipment in use, and dumpster diving. This phase is a part of on-location white box testing only.
• Footprinting: Footprinting consists of active or passive scans to identify various technologies and software deployed on the target, which includes port scanning, banner grabbing, and so on.
• Identifying protection mechanisms: This involves identifying firewalls, filtering systems, network- and host-based protections, and so on.

For more information on gathering intelligence, refer to: http://www.pentest-standard.org/index.php/Intelligence_Gathering.

Threat modeling

Threat modeling helps in conducting a comprehensive penetration test. This phase focuses on modeling out true threats, their effect, and their categorization based on the impact they can cause. Based on the analysis made during the intelligence gathering phase, we can model the best possible attack vectors. Threat modeling applies to business asset analysis, process analysis, threat analysis, and threat capability analysis. This phase answers the following set of questions:

• How can we attack a particular network?
• To which critical sections do we need to gain access?
• What approach is best suited for the attack?
• What are the highest-rated threats?

Modeling threats will help a penetration tester to perform the following set of operations:

• Gather relevant documentation about high-level threats
• Identify an organization's assets on a categorical basis
• Identify and categorize risks
• Mapping threats to the assets of a corporation

Modeling threats will help to define the highest priority assets with risks that can influence these assets.

Consider a black box test against a company's website. Here, information about the company's clients is the primary asset. It is also possible that in a different database on the same backend, transaction records are also stored. In this case, an attacker can use the threat of a SQL injection to step over to the transaction records database. Hence, transaction records are the secondary asset. Having the sight of impacts, we can map the risk of the SQL injection attack to the assets.

Vulnerability scanners such as Nexpose and the Pro version of Metasploit can help model threats precisely and quickly by using the automated approach. Hence, it can prove to be handy while conducting extensive tests.

For more information on the processes involved during the threat modeling phase, refer to: http://www.pentest-standard.org/index.php/Threat_Modeling.

Vulnerability analysis

Vulnerability analysis is the process of discovering flaws in a system or an application. These flaws can vary from a server to the web applications, from insecure application design to vulnerable database services, and from a VOIP-based server to SCADA-based services. This phase contains three different mechanisms, which are testing, validation, and research. Testing consists of active and passive tests. Validation consists of dropping the false positives and confirming the existence of vulnerabilities through manual validations. Research refers to verifying a vulnerability that is found and triggering it to prove its presence.

For more information on the processes involved during the threat-modeling phase, refer to: http://www.pentest-standard.org/index.php/Vulnerability_Analysis.

Exploitation and post-exploitation

The exploitation phase involves taking advantage of the previously discovered vulnerabilities. This stage is the actual attack phase. In this phase, a penetration tester fires up exploits at the target vulnerabilities of a system to gain access. This phase is covered heavily throughout the book.

The post-exploitation phase is the latter phase of exploitation. This stage covers various tasks that we can perform on an exploited system, such as elevating privileges, uploading/downloading files, pivoting, and so on.

For more information on the processes involved during the exploitation phase, refer to: http://www.pentest-standard.org/index.php/Exploitation.

For more information on post-exploitation, refer to http://www.pentest-standard.org/index.php/Post_Exploitation.

Reporting

Creating a formal report of the entire penetration test is the last phase to conduct while carrying out a penetration test. Identifying key vulnerabilities, creating charts and graphs, recommendations, and proposed fixes are a vital part of the penetration test report. An entire section dedicated to reporting is covered in the latter half of this book.

For more information on the processes involved during the threat modeling phase, refer to: http://www.pentest-standard.org/index.php/Reporting.