Unmasking the New Chaos RaaS Group Attacks
Summary:
Cisco Talos Incident Response researchers have uncovered a new ransomware-as-a-service group known as Chaos, active since early 2025, engaging in high-impact, double extortion ransomware campaigns. Despite sharing a name with earlier Chaos builder variants, this group is distinct and more advanced, possibly formed by former BlackSuit ransomware operators. Chaos targets both local and network resources using fast, selective encryption with anti-analysis and privilege escalation techniques. Initial access is gained through low-effort spam campaigns escalating to vishing-based social engineering.
Persistence is maintained through remote monitoring and management tools like AnyDesk and ScreenConnect, while data exfiltration is conducted using tools like GoodSync. The ransomware uses hybrid encryption (Curve25519 + AES-256), custom obfuscation, and deletes shadow copies to prevent recovery. It avoids BRICS/CIS countries and critical sectors like government and healthcare. Chaos is promoted on the RAMP dark web forum and charges a refundable affiliate entry fee. Ransom notes are uniquely crafted per victim and threaten data leaks and DDoS attacks if ransoms aren’t paid.
Security Officer Comments:
The Chaos ransomware group represents an evolving RaaS threat with mature capabilities that mirror the operational structure and tooling of prior high-tier ransomware groups like Royal and BlackSuit. The blend of selective encryption, RMM tool abuse, and phishing-to-vishing escalation showcases a hybrid playbook that minimizes detection while maximizing persistence and impact. Their encryption approach, including peer-to-peer delivery optimization and support for ESXi, NAS, and Linux, reflects enterprise-grade targeting. The similarity in encryption parameters and ransom note structure strongly suggests that Chaos is a rebrand or continuation of BlackSuit operations, which also aligns with the strategic use of brand confusion to evade attribution and mislead defenders.Chaos’s deliberate exclusion of BRICS/CIS targets and the use of Russian-language forums also hint at potential geopolitical affiliations. The group's methodical post-compromise activity discovery, privilege escalation via kerberoasting, defense evasion, and lateral movement using LOLBins, demonstrates a deep familiarity with enterprise networks. Furthermore, the ransom note's narrative (claiming to have conducted a “security test”) is consistent with trends observed in other sophisticated double extortion campaigns that aim to instill fear while appearing “ethical.”
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.
Implement multi-factor authentication (MFA): External-facing assets that leverage single-factor authentication (SFA) are highly susceptible to brute-forcing attacks, password spraying, or unauthorized remote access using valid (stolen) credentials. Implementing MFA enhances security and adds an extra layer of protection.
Link(s):
https://blog.talosintelligence.com/new-chaos-ransomware/
Cisco Talos Incident Response researchers have uncovered a new ransomware-as-a-service group known as Chaos, active since early 2025, engaging in high-impact, double extortion ransomware campaigns. Despite sharing a name with earlier Chaos builder variants, this group is distinct and more advanced, possibly formed by former BlackSuit ransomware operators. Chaos targets both local and network resources using fast, selective encryption with anti-analysis and privilege escalation techniques. Initial access is gained through low-effort spam campaigns escalating to vishing-based social engineering.
Persistence is maintained through remote monitoring and management tools like AnyDesk and ScreenConnect, while data exfiltration is conducted using tools like GoodSync. The ransomware uses hybrid encryption (Curve25519 + AES-256), custom obfuscation, and deletes shadow copies to prevent recovery. It avoids BRICS/CIS countries and critical sectors like government and healthcare. Chaos is promoted on the RAMP dark web forum and charges a refundable affiliate entry fee. Ransom notes are uniquely crafted per victim and threaten data leaks and DDoS attacks if ransoms aren’t paid.
Security Officer Comments:
The Chaos ransomware group represents an evolving RaaS threat with mature capabilities that mirror the operational structure and tooling of prior high-tier ransomware groups like Royal and BlackSuit. The blend of selective encryption, RMM tool abuse, and phishing-to-vishing escalation showcases a hybrid playbook that minimizes detection while maximizing persistence and impact. Their encryption approach, including peer-to-peer delivery optimization and support for ESXi, NAS, and Linux, reflects enterprise-grade targeting. The similarity in encryption parameters and ransom note structure strongly suggests that Chaos is a rebrand or continuation of BlackSuit operations, which also aligns with the strategic use of brand confusion to evade attribution and mislead defenders.Chaos’s deliberate exclusion of BRICS/CIS targets and the use of Russian-language forums also hint at potential geopolitical affiliations. The group's methodical post-compromise activity discovery, privilege escalation via kerberoasting, defense evasion, and lateral movement using LOLBins, demonstrates a deep familiarity with enterprise networks. Furthermore, the ransom note's narrative (claiming to have conducted a “security test”) is consistent with trends observed in other sophisticated double extortion campaigns that aim to instill fear while appearing “ethical.”
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.
Implement multi-factor authentication (MFA): External-facing assets that leverage single-factor authentication (SFA) are highly susceptible to brute-forcing attacks, password spraying, or unauthorized remote access using valid (stolen) credentials. Implementing MFA enhances security and adds an extra layer of protection.
Link(s):
https://blog.talosintelligence.com/new-chaos-ransomware/