Chilean Telecom Giant GTD Hit by the Rorschach Ransomware Gang

Cyber Security Threat Summary:
Chile's telecommunications company, Grupo GTD, has experienced a cyberattack that affected its Infrastructure as a Service (IaaS) platform. The attack caused disruptions to various online services, including data centers, internet access, and Voice-over-IP (VoIP). The attack has been attributed to the Rorschach ransomware gang, which has led to the disconnection of their IaSS platform from the internet. Chile's Computer Security Incident Response Team (CSIRT) has confirmed the ransomware attack and called on public institutions using GTD's IaaS services to report potential impacts. The Rorschach ransomware variant is known for its speed and sophistication, it utilizes DLL sideloading vulnerabilities in legitimate software to load malicious DLLs.

Security Officer Comments:
Although this attack occurred in a different country and outside of the United States, we can draw valuable lessons from similar infrastructure attacks in other regions, such as the recent incidents targeting utilities. Given the increasing prevalence of ransomware and the specific targeting observed, we believe it's essential to inform our members about the tactics, techniques, and procedures (TTPs) utilized by threat groups like Rorschach, including their exploitation of known software vulnerabilities and sophisticated DLL sideloading. This knowledge can empower companies to enhance their defenses and readiness in case these attacks shift their focus to critical infrastructure within the United States.

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.