LitterDrifter, a newly identified worm attributed to the Gamaredon state-sponsored espionage group, has emerged as a concerning threat. This malware, distributed via USB drives, has been implicated in multiple compromises across various countries, including the United States, Ukraine, Germany, Vietnam, Poland, Chile, and Hong Kong.
LitterDrifter: Technical Overview
Written in VBS, LitterDrifter evolves from Gamaredon’s USB PowerShell worm, exhibiting sophisticated techniques to establish communication with the threat group’s command and control server (C2). The worm uses obfuscated VBS components, nesting in the user’s “Favorites” directory to ensure persistence through scheduled tasks and registry keys.
Actions of LitterDrifter
LitterDrifter adopts a two-module approach, employing deceptive LNK shortcuts and hidden copies of “trash.dll” on USB drives. Leveraging the Windows Management Instrumentation (WMI) framework, it identifies target drives and executes malicious scripts through randomized-name shortcuts.
The malware’s unique tactic involves utilizing domains as placeholders for C2 server IP addresses. Before contacting the C2 server, LitterDrifter looks for a configuration file or pings one of Gamaredon’s domains, retrieving the domain’s IP address for communication.
Removal Guide for LitterDrifter
Removing LitterDrifter requires a meticulous approach:
- USB Drive Scanning: Utilize reputable antivirus software to scan and clean USB drives potentially infected with LitterDrifter.
- System Scan: Conduct a comprehensive system scan with updated security software to detect and remove any traces of LitterDrifter on your computer.
Prevention Tips for Mitigating Future Risks
- USB Drive Hygiene: Exercise caution when using USB drives from unknown or untrusted sources. Scan all USB drives before accessing their contents.
- Regular System Updates: Keep your operating system and security software up-to-date to patch vulnerabilities exploited by worms like LitterDrifter.
- Employee Awareness Training: Educate employees about the risks associated with USB drives and train them to identify suspicious files or shortcuts.
- Gamaredon USB PowerShell Worm
- TrashDump Trojan
- DriveCrawler Malware
LitterDrifter’s emergence highlights the evolving sophistication of cyber threats. By adhering to preventive measures, conducting regular system scans, and fostering employee awareness, users can bolster their defenses against similar worm-based attacks, fortifying their systems against potential compromise. Constant vigilance and proactive security measures remain instrumental in mitigating the risks posed by advanced malware like LitterDrifter.