Cyber Security Threat Summary:
Cybersecurity researcher MalwareHunterTeam recently uncovered a new ransomware as a service (RaaS) dubbed SophosEncrypt which is allegedly impersonating Sophos. MalwareHunterTeam Initially thought SophosEncrypt to be part of a red team exercise by Sophos, however, Sophos followed up on Twitter stating that they did not create the encryptor and are conducting an investigation. Taking a closer look at the sample uncovered by MalwareHunterTeam, the encryptor is written in the Rust programming language.

Seeing how SophosEncrypt serves as a RaaS operation, the encryptor upon execution will prompt affiliates to enter a token associated with the victim that is likely first retrieved from the ransomware management panel.

“When a token is entered, the encryptor will connect to 179[.]43[.]154[.]137[:]21119 and verify if the token is valid. Ransomware expert Michael Gillespie found it possible to bypass this verification by disabling your network cards, effectively running the encryptor offline. When a valid token is entered, the encryptor will prompt the ransomware affiliate for additional information to be used when encrypting the device. This information includes a contact email, jabber address, and a 32-character password, which Gillespie says is used as part of the encryption algorithm. The encryptor will then prompt the affiliate to encrypt one file or encrypt the entire device” (Bleeping Computer, 2023).

Security Officer Comments:
The latest strain uses AES-256 CBC with PKCS#7 for encrypting files. Files encrypted by the ransomware are appended with the entered token and email along with the ‘Sophos’ extension. Upon successful encryption, a ransom note is left behind which contains information on how victims can recover their files. The victim’s wallpaper is also changed which displays the group’s brand,

According to Sophos, the strain contains references to a command-and-control server address, which is allegedly an address on the Tor dark web. This address currently hosts the affiliate panel for the operation. The sample uncovered also contains a hardcoded IP address which Sophos says has been associated with both Cobalt Strike command-and-control automated attacks that attempt to infect targeted systems with crypto mining software.

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.

Link(s):
https://www.bleepingcomputer.com/