A remote access Trojan based in JavaScipt avoids identification with a fileless approach. The Trojan is implemented through social engineering. The hackers behind this attack have successfully avoided detection until the winter of 2021.
When was the Attack First Identified?
This digital attack was first identified in mid-November. Though digital security researchers are still attempting to figure out how the malware goes undetected and how its persistence features work, researchers with the Prevailion Adversarial Counterintelligence Team state the malware is likely a tool for initial access and reconnaissance.
How is the Attack Performed?
Researchers with the Prevailion Adversarial Counterintelligence Team have named the malware DarkWatchman. DarkWatchman is concealed as a no-cost notification for storage expiration. The malware is transmitted through spear-phishing emails. The email messages are attached with an invoice as a ZIP archive with the payload used to infect the targeted operating system.
This unique malware employs a domain generation algorithm to pinpoint the command-and-control infrastructure. The malware uses Windows registry for storage capabilities, setting the stage for sidestepping engines that flag malware.
The remote access trojan uses breakthrough methods for attacks without reliance on files. These novel methods also allow for dynamic run-time and on-system activity similar to self-updates and subsequent recompilation.
This remote access trojan is especially dangerous as it is fileless and a C#-based keylogger. C#-based keyloggers are positioned within computer registries so the operators of those machines cannot identify them. These components do not take up much space, making their detection much more challenging. The keylogger is 8.5kb. The JavaScript code is a mere 32kb.
Who is Behind the Malware Attack?
Digital security specialists with Prevailion state the DarkWatchman attack stems from Russia. Prevailion’s team has not named the organization responsible for the attack. The digital security group revealed an enterprise-level organization is likely responsible for the attack.
Why is This Malware Attack so Problematic?
Digital security professionals are concerned about DarkWatchman as it is an advancement in the use of malware attacks without files. This idiosyncratic approach to attacking computers relies on the registry for permanent and temporary storage. Such an approach is unique in that it does not make an imprint on the disk. The malware functions below or near the threshold of detection employed by the vast majority of digital security tools.
This digital attack also has cyber security specialists worried as it removes the need for those behind ransomware to bring in affiliates responsible for adding malware that locks files. Those affiliates also exfiltrate files. DarkWatchman sets the stage for the smooth and efficient deployment of ransomware. The result is the ransomware developers enjoying improved oversight over the operation that allows them to focus on negotiating ransoms rather than executing the subtleties of the attack.