The FBI said that over the last two years, an extortion group known as the Silent Ransom Group has targeted U.S. law firms through callback phishing and social engineering tactics.
This threat outfit, also known as Luna Moth, Chatty Spider, and UNC3753, has been active since 2022. It was also responsible for BazarCall campaigns, which provided initial access to corporate networks for Ryuk and Conti ransomware assaults.
Following Conti's shutdown in March 2022, the threat actors broke away from the cybercrime syndicate and created their own operation known as the Silent Ransom Group.
In recent attacks, SRG mimics the targets' IT help via email, bogus websites, and phone conversations, gaining access to their networks via social engineering tactics. This extortion group does not encrypt victims' systems and is infamous for demanding ransoms in order to keep sensitive information stolen from hacked devices from being leaked online.
"SRG will then direct the employee to join a remote access session, either through an email sent to them, or navigating to a web page. Once the employee grants access to their device, they are told that work needs to be done overnight," the FBI stated in a private industry notification.
"Once in the victim's device, a typical SRG attack involves minimal privilege escalation and quickly pivots to data exfiltration conducted through 'WinSCP' (Windows Secure Copy) or a hidden or renamed version of 'Rclone.'”
After acquiring the victims' data, they use ransom emails to blackmail them, threatening to sell or publish the information. They frequently call employees of breached organisations and force them into ransom negotiations. While they have a dedicated website for disclosing their victims' data, the FBI claims the extortion ring does not always followup on its data leak promises.
To guard against these attacks, the FBI recommends adopting strong passwords, activating two-factor authentication for all employees, performing regular data backups, and teaching personnel on recognising phishing efforts.
The FBI's warning follows a recent EclecticIQ report detailing SRG attacks targeting legal and financial institutions in the United States, with attackers observed registering domains to "impersonate IT helpdesk or support portals for major U.S. law firms and financial services firms, using typosquatted patterns.”
A recent EclecticIQ report about SRG attacks against American legal and financial institutions revealed that the attackers were registering domains to "impersonate IT helpdesk or support portals for major U.S. law firms and financial services firms, using typosquatted patterns." The FBI issued the warning in response to this information.
Malicious emails with fake helpdesk numbers are being sent to victims, prompting them to call in order to fix a variety of non-existent issues. On the other hand, Luna Moth operators would try to deceive employees of targeted firms into installing remote monitoring & management (RMM) software via phoney IT help desk websites by posing as IT staff.
Once the RMM tool is installed and started, the threat actors have direct keyboard access, allowing them to search for valuable documents on compromised devices and shared drivers, which will then be exfiltrated via Rclone (cloud syncing) or WinSCP (SFTP). According to EclecticIQ, the Silent Ransom Group sends ransom demands ranging from one to eight million USD, depending on the size of the hacked company.
