The increase in advanced persistent threat (APT) attacks against small- and medium-sized businesses (SMBs) is becoming a significant concern. Previously, these types of attacks were primarily targeted at large corporations. However, recent trends show that SMBs are now fair game for APT attacks, which are often state-sponsored and pose significant threats to organizations.
To counter these ever-evolving attack vectors, SMBs must consistently update their defenses and be proactive in their cybersecurity measures. This can be a strain on their resources, considering the various tactics, techniques, and procedures (TTPs) used by APTs. APT groups like Cozy Bear (also known as APT29), OceanLotus (also called APT32), and Grim Spider (known as APT-C-37) have the time, money, and resources to conduct technically advanced attacks that can potentially threaten any organization. Furthermore, small businesses can unknowingly become collateral damage for an attack on a larger target.
While some of the APTs’ TTPs are well-known, such as spear phishing, credential theft, living off the land (LOL), and data exfiltration, there are less common TTPs that can wreak just as much havoc. These less commonly known techniques include watering hole attacks, island hopping, fileless malware, hardware-based attacks, zero-day exploits, memory-based attacks, DNS tunneling, advanced anti-forensic techniques, multi-platform or custom malware, and password spraying.
Watering hole attacks involve compromising websites frequently visited by employees of the target organization. The attackers inject malicious code into these legitimate websites, causing visitors to unknowingly download malware. An example of this is the 2013 attack on the website of the US Department of Labor, where visitors’ systems were infected to target government employees and contractors.
Island hopping involves targeting not only the primary victim organization but also other organizations within their supply chain, partners, or affiliates. By compromising less secure third-party companies, APTs can use them as stepping stones to reach the ultimate target and avoid direct detection. Cozy Bear targeted the Democratic National Committee in 2016 and later used island hopping techniques to breach other US government agencies.
Fileless malware resides in the system’s memory, leaving little to no trace on the hard drive. It leverages legitimate processes and tools to carry out malicious activities, making it challenging for traditional security solutions to detect. APT32 (OceanLotus) used fileless malware to compromise multiple organizations in Southeast Asia while evading detection and attribution.
Hardware-based attacks involve compromising firmware, hardware implants, or manipulating peripheral devices to gain persistence and evade traditional security measures. The Equation Group’s malware for reprogramming hard drives’ firmware is an example of a hardware-based attack.
Zero-day exploits target previously unknown vulnerabilities in software or hardware, making them highly effective as no patches or defenses against them are available. The Stuxnet attack, which exploited multiple zero-day vulnerabilities in industrial control systems, is a well-known example.
Memory-based attacks exploit vulnerabilities in software to gain access to sensitive data stored in the computer’s RAM. APT32 is known for using fileless malware and “living off the land” techniques to operate stealthily in the computer’s memory and evade traditional security measures.
DNS tunneling allows APTs to exfiltrate data from the victim’s network by encoding data in DNS requests or responses. This technique allows the attackers to bypass perimeter security measures that may not thoroughly inspect DNS traffic. Cozy Bear used DNS tunneling to communicate with their command-and-control servers and steal sensitive information from targeted organizations.
To cover their tracks and hinder investigation and response efforts, APTs employ advanced anti-forensic techniques. These techniques involve deleting logs, manipulating timestamps, or encrypting data. The Equation Group used a rootkit called “DoubleFantasy” to hide and persistently maintain their presence on infected systems, making it extremely challenging for analysts to detect and analyze their activities.
APT groups also utilize customized malware to maximize their reach. They may have malware capable of targeting both Windows and macOS systems, as well as tailored malware like the Scanbox reconnaissance framework. APT1, also known as Comment Crew or Unit 61398, utilized custom malware to infiltrate and steal sensitive data from various organizations worldwide.
Password spraying attacks are used to gain initial access by attempting to use a few common passwords against multiple accounts. APT33 (Elfin) used password spraying to compromise email accounts in the Middle East and globally, gaining a foothold for further cyber-espionage activities.
To counter APT attacks, organizations should adopt a comprehensive defense-in-depth strategy. This strategy includes implementing multiple layers of security controls, such as strong perimeter defenses, network segmentation, endpoint protection, intrusion detection systems, data encryption, access controls, and continuous monitoring for anomalies.
Additionally, organizations should actively participate in threat intelligence sharing communities. Collaborating with industry peers, government agencies, and security vendors can help organizations detect and mitigate APT attacks effectively by sharing information about APTs and their techniques.
Regular security awareness programs, phishing simulations, and training sessions can educate employees about the latest threats, social engineering techniques, and safe computing practices. This helps create a human firewall against APT attacks.
Despite preventive measures, organizations should have a well-defined incident response plan. This plan includes incident detection, containment, eradication, and recovery procedures to minimize the impact of APT attacks and restore normal operations.
In conclusion, APT attacks against SMBs are on the rise, and organizations must be prepared to defend against these sophisticated threats. Understanding the various TTPs used by APT groups, as well as implementing comprehensive defense strategies, sharing threat intelligence, educating employees, and having strong incident response capabilities, are essential components of effective APT defense. By remaining vigilant and having the necessary technical expertise, organizations can enhance their defense strategies and safeguard against these persistent threats.