Cybersecurity vendors, law enforcement agencies, and regulators all around the globe stick to the following classification of threats:
- APTs
- Cybercriminals
- Hacktivists
- Competitors
- Insider threats
- Terrorist groups
- Script kiddies
Let’s take a closer look at each.
APTs
There are two types of APT groups: nation-state and non-nation-state.
Nation-state groups are also classified as APTs; we will describe their key differentiators shortly. Nation-state threat actors’ main motivation is data. They conduct espionage to steal intellectual property, spy on the targets, and gather state secrets and other confidential information. In some cases, they disrupt business or demand some ransom but are still founded by government authorities.
Note
For more details, please read the Microsoft threat research about MuddyWater cooperating with another cyber threat actor (https://www.microsoft.com/en-us/security/blog/2023/04/07/mercury-and-dev-1084-destructive-attack-on-hybrid-environment/). Earlier, we looked at the main motivations of state-sponsored APT threat groups. However, there are a few exceptions. Lazarus, the North Korean nation-state group, is mainly motivated by financial gain (https://securelist.com/lazarus-trojanized-defi-app/106195/ and https://www.group-ib.com/resources/research-hub/lazarus/).
Not all nation-state groups are sophisticated. Some of them may use script-kiddie-level techniques that are usually easily detected by security controls but will be ignored by in-house cybersecurity teams due to their lack of skills.
Non-nation-state threat actors are also considered APTs but they are not founded by government authorities. They are also called cyber-mercenaries or hack-for-fire since they offer their hacking services to the highest bidder, often conducting cyberattacks, espionage, or other malicious activities on behalf of clients, which can include other criminals, businesses, or even nation-states. As an example, RedCurl’s threat actor campaigns’ main goals were to steal confidential corporate documents such as contracts, financial documents, records of legal actions, and personal employee records. This was a clear indicator that RedCurl’s attacks might have been commissioned for corporate espionage.
The following are some key features of APTs:
Note
As an example, the nation-state-sponsored group APT29 disabled mailbox audit logging to hide their access to emails and other activities from a compromised account.
Cybercriminals
By the end of the 2010s, financial crimes faced a dramatic issue in monetizing their activities as financial institutions significantly improved their security postures, which increased the cost of attacks. Moreover, SWIFT payments are easy to track, require a lot of effort in terms of money laundering, and have greater risks and commissions split across different parties (for example, mule services). Under these circumstances, threat actors started searching for various methods of downsizing the attack period, its complexity, and how easy it was to collect money from victims. The idea was extremely easy – why would the victims not pay a ransom demand to the threat actor themselves rather than searching for a way to transfer money from their accounts? For example, they could heavily impact the business – disrupt business processes, exfiltrate sensitive information, and more. Such an idea made for a sensational shift in the cyber threat landscape as ransomware gangs took the floor. We will discuss ransomware and other cyberattacks in this section.
Ransomware
According to the vast majority of cybersecurity vendors, ransomware is a primary threat facing private and, increasingly, public sector organizations. This type of threat actors’ main motivation is financial gain. The ransom amount varies greatly, depending on the type of victim. In the case of a simple user, the range will be 500 to 1,000 US dollars. When it comes to organizations, the price depends on the revenue and threat actor appetites. It usually starts from $5,000 and can sometimes reach up to £100,000,000. All ransoms are demanded in cryptocurrencies such as Bitcoin and Ethereum, and sometimes in Monero. After receiving the payment, most adversaries send either a key for decryption or a decryptor tool. However, there are always exceptions to the rules: no one can guarantee the honesty of the attackers or the correct implementation of the encryption algorithm. We have been engaged in several cases when even a threat actor failed to decrypt the data using the correct key. At the same time, there is almost zero chance to decrypt data without paying a ransom. Law enforcement agencies or cybersecurity vendors may gain access to the key database stored on the C2 servers of threat actors, there might be a mistake in the encryption algorithm’s implementation, secrets aren’t managed securely, or there isn’t an offline backup of the most crucial data.
The median detection window for ransomware attacks in 2022-2023 stands at around 4-9 days according to different vendors and their observations (https://cloud.google.com/security/resources/m-trends and https://www.group-ib.com/landing/hi-tech-crime-trends-2023-2024/). In many cases, detection happens after discovering the impact caused by the attack. The attack timeline varies, depending on the complexity and level of attack automation. There are dozens of research papers, trend reports, and even books related to this topic that have been published in the past years. For now, let’s learn how to classify ransomware attacks.
First, we have automated attacks and malware bundles. These are spread across hundreds or thousands of malicious websites via file hosting services, fake updates, Trojanized applications, or mass spear-phishing campaigns that are sent to tens to hundreds of thousands of users. Here are the most recent articles describing malicious campaigns:
- https://www.group-ib.com/blog/malware-bundles/: This article describes the spread of a malware bundle containing information stealers such as RedLine, AZORult, Vidar, Amadey, Pony, qbot (that is, QakBot), Raccoon stealer, remote access Trojans such as AsyncRAT, Glupteba, njRAT, and nanocore, and other payloads such as miners, keyloggers (HawkEye) and ransomware (DJVU/STOP). Figure 1.1 explains the malware bundle packaging mechanism. The ransom demands in such cases rarely exceed $1,000. However, the key risk is hidden in compromising all the stored credentials and leaving a backdoor that could later be used by other threat actors to run more sophisticated attacks that target not only individuals but the organization. We have observed similar infections on IT administrators’ corporate devices. Once, there was a sale on a dark web forum offering access to the backdoor of an IT administrator’s device that served more than 50 banks in the MEA region for $20,000. At the end of the day, the attack was averted through a joint effort with FinCERTs and potentially affected customers. The following figure shows an example of malware bundle packaging:
Figure 1.1 – Malware bundle packaging example
A more sophisticated type of attack is human-operated ransomware. These attacks are conducted by full-fledged, well-organized teams with well-developed task delegation, thorough testing and standardization of the attack process, and scrupulous team selection. They provide clear terms of partner programs for outsourcing certain tasks, such as using initial access brokers, who provide them with access to the compromised organization’s networks (for example, IcedID, QakBot, BazarLoader, Emotet, TrickBot, Dridex, Hancitor, ZLoader, and SocGholish) purchase compromised credentials available on dark web forums, and use pentesters for privilege escalation and preparation for enterprise-wide ransomware deployment or negotiators to agree on the ransom demand. Such attacks include human interaction while gaining ultimate access and preparing for enterprise-wide ransomware deployment. This includes creating a domain group policy object (GPO), attaching shared storage with virtual machine disks, or preparing SSH access for VMWare ESXi nodes. There are two significant trends in human-operated ransomware:
- In 2014, Iranian threat group SamSam introduced a trend in human-operated attacks called Big Game Hunting
- Starting in 2017, a ransomware called BitPaymer, associated with a cybercrime group called Evil Corp, gained popularity while following a similar approach to SamSam
- Starting in 2019, there has been a rise in Ransomware-as-a-Service (RaaS) programs
There are many arguments about whether human-operated ransomware attacks are considered sophisticated. Cl0p (FIN11), FIN12, BlackCat, Black Basta, LockBit, AvosLocker, Royal Ransomware, and others aggregated thousands of successful attacks on their victims using tailored approaches to key targets. Many RaaS operators used to recruit new affiliates on underground forums. However, in 2021, they started doing this more privately to complicate the jobs of security researchers and law enforcement in terms of tracking them. They invest a lot in developing tools for hybrid infrastructures (Windows, Linux, macOS, VMWare, and others). In addition, they deploy guidelines for new teams to follow the steps from the initial foothold to preparing for an enterprise-wide ransomware deployment. A conti ransomware case that was quite interesting was the one where one of the group members leaked their guides to the public, which allowed many cybersecurity researchers and vendors to understand their structure and methods in more detail. To hide their activity, such actors utilize dual-use tools to mimic IT administrators’ activities and perform deep gap analysis, which is followed by various defense evasion techniques such as impairing defenses by blinding or uninstalling AV and EDR solutions. In some cases, ransomware reboots the endpoint into safe mode to ensure no security products interfere with the encryption process.
When it comes to extortion techniques, most groups use double extortion by demanding a ransom payment for data decryption and exfiltrating sensitive data by exposing a small part of it on their data leak site (DLS). A new trend set by LockBit in 2022 opened a world of opportunities to put more pressure on the victim to pay a ransom by launching a distributed denial of service (DDoS) attack against it. The ransom was tied to the organization’s revenue, which was usually gained from B2B databases containing company contacts and intelligence, or cyber insurance levels.
Other financially-motivated groups
Such groups usually have unique monetization strategies directly enabled by data theft. They often steal financial data or files related to a company’s point-of-sale (POS) systems, ATMs, remote banking services, payment card data, and general financial transaction processing systems. They also demonstrate the capability to deploy custom-developed tools and utilities that have been crafted to support their goals in victim environments. Like APTs financially motivate threat actors, they have extended dwell times and evolving TTPs so that they can conduct attacks. Of course, this may vary, depending on the group’s objectives. Silence, FIN13, FIN6, FIN7 (before they shifted their focus to ransomware), FIN8, FIN13, MoneyTaker, CobaltGroup, and Buhtrap are good examples of this class of threat actors.
Some groups (for example, Buhtrap) target accountants and lawyers by either infecting web resources these employees use in their professional activities or conducting SEO-poisoning attacks (https://www.crowdstrike.com/cybersecurity-101/attack-types/seo-poisoning/) and spreading infected office documents via several templates. As a result of the attack, they successfully compromise digital certificates, submit rogue payments that pass all checks, and proceed with processing. In some campaigns, it was observed that attackers were injecting invisible iframes into the web page of the bank and seamlessly replaced payment information, which also resulted in rogue payments being confirmed by the accountants.
Another type of financially motivated group with a lower attack complexity level is business email compromise (BEC). Overall, such actors practice phishing, social engineering, and business email compromise scams to deceive their targets and steal money or sensitive information. It starts with a phishing attack or a valid account being purchased from initial access brokers. This results in them logging in to the mailbox, at which point they can reroute the communication channel between parties to the fake email accounts impersonating each party, thus implementing a man-in-the-middle (MiTM) attack via email and then guiding a victim to change the recipient’s bank account details and making a money transfer. We won’t cover such types of attacks in this book as they have never been seen targeting Windows systems in their attacks before.
More sophisticated attacks included compromising SWIFT and other regional-specific financial messaging platforms by submitting malicious transaction files or details at various gateways (for example, FIN7, FIN8, and Lazarus). One of the most notable cases was an attack on the Central Bank of Bangladesh by Lazarus (https://www.group-ib.com/blog/lazarus/). It usually starts with spear-phishing or exploiting vulnerabilities at an external attack surface while performing a deep dive into the victim’s network (mostly at the IT segment), utilizing a mix of living-off-the-land techniques and customized backdoors and discovering a path to the target network segment, gaining full visibility into their operations, preparing for the impact, and then implementing it. These attacks may last for years before they achieve their goal. However, thanks to huge efforts by the financial sector, regulators, and law enforcement agencies, the costs of these have attacks increased dramatically and their efficiency has been reduced. This has led to ransomware being used by most financially motivated groups.
Hacktivists
Hacktivists are individuals or groups that use cyberattacks as a form of protest, to promote a particular cause, or to gain attention for their beliefs. They often target organizations they perceive as corrupt or unjust. Hacktivists are hacker groups that work together anonymously to achieve a certain objective. They use hacking and other cyber techniques to promote their beliefs, raise awareness, or influence public opinion. Examples of such techniques include DDoS attacks (https://www.group-ib.com/blog/middle-east-conflict-week-1/), website defacing, and leaking confidential information and publishing it on social networks or as web resources. Such campaigns usually occur during wars, revolutions geopolitical conflicts, and social movements. Their attack techniques are usually not sophisticated, they exploit public-facing vulnerabilities, find common misconfigurations, or use weak authentication to perform brute-force or password-spraying attacks to gain access to the web interface of a web resources’ content management systems (CMSs). When hacktivist groups work together, they may perform a DDoS attack. In some cases when a DDoS attack happens, a hacktivist group may claim responsibility for it, but they don’t provide any proof.
Competitors
These include rival organizations or businesses that engage in cyber espionage or other malicious activities to gain a competitive advantage in the marketplace. They usually perform passive attacks by eavesdropping, utilizing shared platforms, or using other publicly available information. The active phases of their attacks include social engineering and the use of insiders. They are extremely careful in terms of NDA violation and try to avoid their rivals’ infrastructure manipulation as this may lead to their activity being exposed. For example, a microfinance institution uses a common shared database of credit bureaus, SMS gateways, and MQL platforms. Their competitors may spot any activity on the organization’s end and send an offer to the customer with better terms. From our experience, such attacks are extremely tough to investigate as there is usually a lack of data flow management, visibility, commercial secrets hygiene, and involvement of multiple third parties with limited responsibility. Moreover, employees may use their devices, SIM cards, or social media accounts to perform multiple business-related activities. Once they are suspected, the organization must have solid evidence to acquire these devices for forensic investigation; otherwise, it may lead to disrupting employees’ loyalty and causing them to search for new jobs.
Insider threats
These are individuals within an organization who misuse their authorized access to systems or data, either intentionally or unintentionally. They can cause significant damage due to their knowledge of the organization’s internal structure and security measures. As discussed previously, they may cooperate with competitors and be guided by them. In some cases, insiders get paid by cybercriminals (https://www.bleepingcomputer.com/news/security/lockbit-ransomware-recruiting-insiders-to-breach-corporate-networks/) to download and run some malware or disclose some infrastructure details, as well as share credentials. From an incident investigation perspective, it is quite complicated to prove that a user has done this due to a lack of digital hygiene knowledge, not due to them getting paid by other parties. In addition, once cybercriminals or APTs have gained an initial foothold, they try to compromise the privileged accounts of IT administrators and utilize them in the attack. From our experience, cybersecurity divisions are willing to become suspicious about some employees when no evidence can prove employees’ innocence. Once, we were involved in a business email compromise incident that targeted internal employees and some external customers. The employer escalated the case to law enforcement agencies and made formal accusations against an employee. Fortunately, the initial access was identified, and it proved to be a massive campaign from an unknown gang. Further cooperation with law enforcement agencies led to the group being spotted. The final report was used by attorneys; it proved the innocence of the employee and the case was closed.
On the contrary, there was a case where a FIN actor conducted a targeted spear-phishing campaign against a company IT administrator who was familiar with cybersecurity concepts. Despite this, they opened the email on their corporate device, downloaded the attachment, and executed it. This eventually led to a successful attack and the withdrawal of several million dollars. Upon initial analysis of this attachment, it became apparent that it was Cobalt Strike malware. The Department of Cybersecurity decided to launch a criminal case against an employee, which resulted in their arrest on suspicion of assisting the attackers.
There was also a case where an employee, when they moved to a competitor, took a customer database that was stored in a cloud database. The investigation was complicated by the fact that the employees were working from personal Google accounts, personal smartphones, and a corporate laptop. The NDA agreement did not prohibit the use of personal devices, and the exit procedure didn’t include any device checks for the remaining commercial secrets. In addition, no legal documents were signed. After discovering the leak in the customer database (a competitor began contacting VIP customers and offering them better terms), an internal investigation was conducted, which found that the employee didn’t access corporate data after being terminated and that the IT department hadn’t restricted the ex-employee’s access to the database. As a result, everyone knew the person was guilty, but there was no legal reason to hold them accountable.
You might be wondering how these cases are relevant to this book, but we will use their lessons learned to explain the investigation process and other important steps every organization should take to secure its data from threat actors, especially in Windows environments.
Terrorist groups
These are extremist organizations that use cyberattacks in support of their ideological goals. They don’t possess the same level of sophistication as nation-state APT groups, but they can still cause significant harm. Their goals are to perform website defacement, DDoS attacks, data breaches and leaks, cyber espionage, sabotage and disruption, radicalization, and social media manipulation.
Script kiddies
These are inexperienced or unskilled individuals who use pre-made tools, scripts, or exploits to conduct cyberattacks. They typically lack the technical knowledge to create attack methods and often target systems with known vulnerabilities. Their main motivation is to gain experience, build their portfolio, and attempt to join more mature cybercrime syndicates.
Organizations with an average level of cybersecurity can easily resist these types of attackers because their methods are easily detectable, lack uniqueness, and are not targeted. Most techniques can be prevented with security controls. Analysts must ensure that their attacks have been mitigated and they have no other foothold.
There was a case when two cybercriminals worked together on an attack and successfully encrypted a logistics company by putting all of Microsoft Hyper-V’s virtual machine disks into one VeraCrypt container. They contacted their victim, offering to provide a container decryption key and secret. However, it didn’t work, so they requested access to the dedicated server that held the container via a remote administration tool and tried to decrypt it themselves. But this also failed. The initial access vector was external remote services, RDP published to the outside with weak authentication (an 8-digit password for the local administrator and no brute-force protection). Attackers used their personal computers from home while not considering the use of public proxy, VPN, TOR, or hosting provider’s VPS/VDS. Once this was escalated to law enforcement and some joint investigation was conducted, they were caught and arrested.
The lesson to be learned here is that every attack should be properly investigated by professionals as they may identify the threat actor’s maturity, find their mistakes, and proceed with law enforcement agencies to make our cyberspace a little safer.
Wrapping up
With that, we have discussed various threat actor types and their key motivations. Looking at the different levels of maturity of attackers revealed that it is sufficient to implement basic best practices to prevent their attacks. For example, installing an antivirus (AV), running regular vulnerability scans with a proper patch management process, checking for compromised credentials on EASM and acting accordingly, securing email with anti-spam and sandbox solutions, implementing strong password policies and running continuous cybersecurity hygiene exercises with employees, and having proper incident response plans, even for low-mature cybersecurity teams, may prevent script kiddies, terrorist, hacktivists, and some competitor attacks. APTs and cybercrime threat actors can easily bypass this cybersecurity posture and will require significantly more effort from the cybersecurity team and organization management.
The following are some key lessons learned for organizations:
- There should be an inventory of key assets and business processes, as well as a thorough understanding of the data flow.
- The cyber threat landscape is a continuous process and requires dedicated resources or regular engagements to be kept up to date.
- It is critical to perform regular gap analysis while focusing on security control coverage, lack of visibility, proper incident response procedures, and mitigation strategies.
- There should be a proper external attack surface management process that covers all vulnerabilities that have been discovered and patched promptly and ensures no credentials are exposed or haven’t been resolved and that no explicit resources are exposed to the internet.
- There are no silver bullets that can ensure 100% protection from cyber threats, such as installing AV or EDR and relying on automated cyber-attack prevention.
- Intelligence-driven incident response and cybersecurity strategies are more cost and time-efficient than other approaches, providing valuable insights that enable organizations to have better defenses.
To summarize, by understanding the maturity level of attackers, the degree of sophistication of their attacks, and their motivations, we can better understand the purpose and contents of the threat landscape and begin to build a relevant one for our organization.