Summary:
A recent report from Group-IB reveals that RansomHub emerged as the most active ransomware group of 2024, targeting over 600 organizations across various sectors, including healthcare, finance, government, and critical infrastructure. RansomHub initiated operations in early February 2024, shortly after coordinated law enforcement efforts dismantled the infrastructure of the BlackCat and LockBit ransomware groups, both of which were among the most active at the time. Taking advantage of the disruption caused by these law enforcement actions, RansomHub has successfully recruited affiliates from the defunct LockBit and BlackCat networks. Affiliates are typically responsible for gaining initial access to victim environments and deploying the encryptor on behalf of ransomware group they are affiliated with. In return, they get a portion of the ransom paid by victims. Notably, RansomHub offers affiliates 90% of the ransom, keeping only 10% for itself, far above the industry average of 75%. As more affiliates join RansomHub's ranks, the group continues to compromise dozens of organizations worldwide, with the number of attacks rising daily.

Security Officer Comments:
RansomHub is known for exploiting known vulnerabilities and weak credentials to gain initial access to organizational networks. In an incident analyzed by Group-IB, RansomHub first attempted to exploit a critical vulnerability in Palo Alto Networks PAN-OS devices (CVE-2024-3400) using a publicly available proof-of-concept. However, the attack failed, and the actors ultimately gained access to the victim network through a brute-force attack on the VPN service, using a dictionary of over 5,000 usernames and passwords. They successfully breached the network via a default account commonly used in data backup solutions. Once inside, RansomHub launched its ransomware, encrypting and exfiltrating data within 24 hours. Notably, the attackers employed PCHunter to disable and bypass endpoint security solutions and used FileZilla, an open-source file transfer tool, to exfiltrate the stolen data. Additionally, RansomHub leveraged two known security vulnerabilities in Active Directory (CVE-2021-42278, "noPac") and the Netlogon protocol (CVE-2020-1472, "ZeroLogon") to seize control of the domain controller and conduct lateral movement across the network.

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 on how to avoid and spot phishing emails. Multi-factor authentication can help prevent malicious access to sensitive services.

Link(s):
https://www.group-ib.com/blog/ransomhub-never-sleeps-episode-1/