Cyber Security Threat Summary:
The LockBit ransomware group has leaked 1.5 terabytes of personal and financial data from Bank Syariah Indonesia (BSI) after failed ransom negotiations. The stolen data includes information from approximately 15 million customers and employees of the country's largest Islamic bank. BSI has restored its key banking services under the supervision of Bank Indonesia. BSI initially experienced disruptions due to a cyberattack, but LockBit claims the bank misled customers by attributing the issues to technical maintenance. The leaked conversations between the bank and ransomware group reveal that BSI considered paying $10 million to retrieve the data, while LockBit demanded $20 million. Indonesian Vice President Ma'ruf Amin urged BSI to enhance its technology to prevent future attacks.

Security Officer Comments:
The LockBit ransomware group leaked a large amount of sensitive information from Bank Syariah Indonesia, which is a major threat to the affected customers and employees. Ransomware attacks are becoming more advanced, and when negotiations failed, the attackers resorted to leaking the data. Initially, the bank blamed the disruptions on maintenance instead of admitting it was a cyberattack, which could harm its reputation and customer trust.

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.bankinfosecurity.com/lockbit-leaks-15tb-data-stolen-from-indonesias-bsi-bank-a-22110