Summary:
The Inc ransomware group recently carried out a significant cyberattack on McLaren Health Care, a multibillion-dollar healthcare network operating across Michigan, Indiana, and Ohio. The attack severely disrupted McLaren's IT and phone systems, forcing hospitals and outpatient clinics to implement "downtime procedures." These procedures included rescheduling nonemergency appointments, tests, and treatments, and asking patients to bring physical copies of their medical records, such as test results and imaging, to ensure continuity of care.

Initially, McLaren did not disclose whether sensitive patient or employee data had been compromised in the attack. However, a hospital employee leaked a printed ransom note, revealing that the Inc ransomware group was holding the organization's data hostage. Despite repeated attempts, McLaren has yet to provide an update on the situation.

Interestingly, victims of Inc's ransomware attacks may have a chance to recover their data without paying the ransom. According to a recent report from GuidePoint Security, Inc's encryptor leaves behind an 80-byte footer on encrypted files that leaks crucial information about the encryption process. This footer can indicate whether the file was encrypted at a "Fast," "Medium," or "Slow" pace, with fast encryption only affecting specific parts of the file (the first, middle, and last megabyte), and slower encryption targeting the entire file. This leaked information allows victims to make informed decisions about how to proceed with data recovery.


Security Officer Comments:
For example, if the footer suggests that a file was encrypted quickly, victims might be able to recover most of the file's content using commercial forensic tools without needing Inc's decryptor. However, if the file is encrypted and lacks this footer, it likely means the file has been corrupted and is beyond recovery, even with a decryptor. GuidePoint Security's consultant, Jason Baker, emphasizes the importance of examining these footer values before attempting decryption to gauge the likelihood of successful recovery.


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.darkreading.com/cyberat...cryptor-contains-keys-to-victim-data-recovery