Cybersecurity experts have raised alarms over a rise in attacks involving ValleyRAT, a Remote Access Trojan (RAT) linked to the Silver Fox advanced persistent threat (APT) group. Recent campaigns have seen the malware use more sophisticated delivery methods, targeting key departments within organizations, especially finance and accounting. Reports from Morphisec Threat Labs reveal that ValleyRAT has become more potent, with refined techniques designed to improve its chances of infiltration and persistence within corporate networks.
The infection process begins when users are tricked into downloading software that masquerades as legitimate applications, often impersonating popular programs like Google Chrome. Malicious websites, such as those hosted on domains like “anizom[.]com,” deliver fake installers that, once executed, deploy a multi-stage payload hidden in files like “sscronet.dll” and “douyin.exe.” The malware uses these files to bypass detection by security systems and avoid raising suspicion, placing the payload in system directories where it can remain dormant while it spreads.
Once ValleyRAT is deployed, it uses several advanced techniques to evade detection. It employs DLL search order hijacking, using legitimate signed executables to inject malicious code into critical system processes. This process is further concealed by integrating game files from titles like “Left 4 Dead 2” to avoid scrutiny. Additionally, the malware includes memory injection tactics and modifies Windows system registries to ensure its persistence.
It also uses keylogging to steal sensitive information, further emphasizing its targeted approach to capturing valuable data, especially from finance departments.
The focus on finance and accounting departments shows that the Silver Fox group is deliberately aiming to compromise areas within organizations that manage sensitive financial data. The use of ValleyRAT highlights the increasing sophistication of cyberattackers and their ability to bypass traditional security measures. To combat these threats, experts recommend that businesses adopt adaptive, layered security models, such as Moving Target Defense (MTD), to proactively counter the evolving tactics used by these advanced cybercriminals.
