Rust-Written 3AM Ransomware: A Sneak Peek into a New Malware Family

Cyber Security Threat Summary:
A new ransomware family called 3AM has emerged in the wild after it was detected in a single incident in which an unidentified affiliate deployed the strain following an unsuccessful attempt to deliver LockBit (attributed to Bitwise Spider or Syrphid) in the target network. 3AM gets its name from the fact that it's referenced in the ransom note. It also appends encrypted files with the extension .threeamtime. That said, it's currently not known if the malware authors have any connections with known e-crime groups. In the attack spotted by Symantec, the adversary is said to have managed to deploy the ransomware to three machines on the organization's network, only for it to be blocked on two of those machines. The intrusion is notable for using Cobalt Strike for post-exploitation and privilege escalation, following it up by running reconnaissance commands to identify other servers for lateral movement. The exact ingress route employed in the attack is unclear” (The Hacker News, 2023).

Security Officer Comments:
3AM is a 64-bit executable written in the Rust programming language. Rust has become a popular choice among ransomware groups due to it being difficult to analyze and an overall low detection rate by antivirus solutions. As such, several ransomware groups have come out with Rust variants including BlackCat, Hive, Luna, RansomExx, and much more. According to Symantec, the latest strain comes with various commands designed to stop various processes including security and backup-related software. Like any other ransomware strain, 3AM will also purge shadow volume copies making recovery difficult. It is unclear if 3AM has a dedicated data leak site. However, researchers noted that the actors use the Wput tool to exfiltrate victims’ files to a detected FTP server.

Suggested Correction(s):
Backup your data, system images, and configurations, regularly test them, and keep the backups offline: Ensure that backups are regularly tested and that they are not connected to the business network, as many ransomware variants try to find and encrypt or delete accessible backups. Maintaining current backups offline is critical because if your network data is encrypted with ransomware, your organization can restore systems.

Update and patch systems promptly: This includes maintaining the security of operating systems, applications, and firmware in a timely manner. Consider using a centralized patch management system; use a risk- based assessment strategy to drive your patch management program.

Test your incident response plan: There's nothing that shows the gaps in plans more than testing them. Run through some core questions and use those to build an incident response plan: Are you able to sustain business operations without access to certain systems? For how long? Would you turn off your manufacturing operations if business systems such as billing were offline?

Check Your Security Team's Work: Use a 3rd party pen tester to test the security of your systems and your ability to defend against a sophisticated attack. Many ransomware criminals are aggressive and sophisticated and will find the equivalent of unlocked doors.

Segment your networks: There's been a recent shift in ransomware attacks – from stealing data to disrupting operations. It's critically important that your corporate business functions and manufacturing/production operations are separated and that you carefully filter and limit internet access to operational networks, identify links between these networks and develop workarounds or manual controls to ensure ICS networks can be isolated and continue operating if your corporate network is compromised. Regularly test contingency plans such as manual controls so that safety critical functions can be maintained during a cyber incident.

Train employees: Email remains the most vulnerable attack vector for organizations. Users should be trained how to avoid and spot phishing emails. Multi Factor authentication can help prevent malicious access to sensitive services.