Summary:
On December 4, 2024, the ransomware group Brain Cipher publicly claimed responsibility for a breach allegedly targeting Deloitte UK. The group, which specializes in extortion and operates ransomware strains derived from LockBit 3.0, asserted that it had stolen 1TB of compressed data. It threatened to publish the information unless Deloitte engaged with the group by December 15. Deloitte swiftly refuted the claims, clarifying that their investigation determined the alleged compromise involved a single client system that was not part of Deloitte’s infrastructure. They emphasized that no internal Deloitte systems were breached or affected. Brain Cipher, a group emerging earlier in 2024, has previously been linked to similar high-profile attacks, employing multi-extortion tactics designed to maximize reputational and operational damage to their targets (Infosecurity Magazine, 2024).

Analyst Comments:
The incident highlights a prevalent tactic among cybercriminal groups, where they attribute breaches to high-profile organizations to amplify their notoriety and instill fear. This practice can have wide-ranging consequences, including damaging reputations, influencing stock prices, and prompting costly investigative and legal responses. Analysts emphasize the importance of distinguishing between claims targeting clients or suppliers and direct breaches of organizations. This differentiation is critical as both criminal and state-sponsored actors have been known to misrepresent client-related incidents as compromises of larger organizations. Deloitte’s proactive response underscores the importance of clear communication and transparency in mitigating potential fallout from such allegations (Infosecurity Magazine, 2024).

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.infosecurity-magazine.com/news/deloitte-denies-breach-claims/