Summary:
Researchers at Symantec have uncovered similarities between two ransomware families, RansomHub and Knight, indicating a potential rebrand of the now defunct Knight ransomware which went silent after its source code was listed for sale on hacker forums back in February 2024. Similar to Knight ransomware, RansomHub is written in the Go programming language. Taking a look at the source code for both strains, Symantec observed extensive code overlaps between the two malware payload strings. Both Knight and RansomHub ransomware use a unique obfuscation technique where important strings are encoded with unique keys. The ransom notes left by the two ransomware strains are fairly similar, with researchers noting that minor updates have been added to RansomHub. Notably, the command-line menus employed by these two payloads are nearly identical, with the only exception being the addition of the ‘sleep’ command on RansomHub.

Security Officer Comments:
RansomHub first appeared in February 2024, around the same time that Knight ransomware’s source code was listed for sale. Since then, operators of this strain have made a name for themselves, listing several victims to their data leak site, including Change Healthcare, NRS Healthcare, and telecom giant Frontier communications as of recently. While RansomHub did not directly breach Change Health, earlier this year affiliates of the BlackCat ransomware strain seeked the help of RansomHub to relist data stolen from Change Healthcare, after administrators of BlackCat ran away with the initial ransom paid without paying affiliates. Since then affiliates of BlackCat including Notchy and Scattered Spider have joined the ranks of RansomHub, enhancing the operational capabilities of the ransomware gang.

Suggested Corrections:
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/ne..gang-linked-to-now-defunct-knight-ransomware/