GreenBlood is a modern ransomware first identified in early 2026 and known for its rapid system disruption and recovery prevention that focuses mainly on file encryption. GreenBlood actively sabotages system recovery mechanisms and security controls before or during encryption, significantly increasing the impact on victims.
Summary
GreenBlood is a modern ransomware first identified in early 2026. It’s known for its rapid system disruption and recovery prevention. Unlike basic ransomware that focuses mainly on file encryption, GreenBlood actively sabotages system recovery mechanisms and security controls before or during encryption, significantly increasing the impact on victims.
Behavioral Summary
One of the first actions performed by GreenBlood is system profiling. The malware collects a unique hardware identifier (system UUID) using standard Windows tooling. This identifier allows attackers to inventory infected machines, correlate victims with ransom records, and manage encryption keys more efficiently across campaigns.
To ensure recovery is difficult or impossible, GreenBlood aggressively targets backup and restore capabilities. It will delete all Volume Shadow Copies and remove the Windows Backup catalog, effectively neutralizing both user-created restore points and system-level backups. This prevents victims from rolling back files or restoring the system without external backups, thus increasing the pressure to pay the demanded ransom.
GreenBlood further strengthens recovery inhibition by disabling the Windows Recovery Environment (WinRE) and suppressing boot failure warnings. These changes block access to automated repair tools and rollback options that might otherwise help victims recover after the attack or troubleshoot the system.
The ransomware also actively weakens system defenses by disabling the Windows Firewall, allowing unrestricted inbound and outbound network traffic. This results in facilitating command-and-control communication, data exfiltration, or lateral movement within a network. In addition, GreenBlood disables Microsoft Defender’s real-time protection through registry modifications, reducing the likelihood of detection or intervention during execution.
Once encryption is complete, affected files may be appended with the .tgbg extension. A ransom note named !!!READ_ME_TO_RECOVER_FILES!!!.txt is dropped into every directory containing encrypted files, ensuring the victim encounters the ransom message regardless of where they navigate.
(Example of Ransom Note | Source: https://community.broadcom.com/viewdocument/tau-tin-greenblood-ransomware?CommunityKey=3bd4783a-2be9-4de0-a8b9-893f8e815743)
Finally, GreenBlood attempts to erase its own footprint. It drops a cleanup batch file (cleanup_GreenBlood.bat) into the system’s temporary directory and executes it after encryption finishes. This removes the ransomware binary and related artifacts, complicating forensic analysis and incident response efforts.
Below is a list of command lines utilized by GreenBlood during an attack: (Source: https://community.broadcom.com/viewdocument/tau-tin-greenblood-ransomware?CommunityKey=3bd4783a-2be9-4de0-a8b9-893f8e815743)
Conclusion
GreenBlood is a highly disruptive ransomware strain that prioritizes defense evasion, recovery denial, and victim tracking as much as encryption itself. Its methodical disabling of backups, recovery tools, firewall protections, and antivirus defenses makes post-infection remediation especially challenging, aligning it with more advanced and professionally operated ransomware campaigns.
What DefenseStorm Is Doing
The DefenseStorm team will continue to monitor additional developments and information regarding this emerging threat. All currently available IPs and hashes associated with this threat have been uploaded to the DefenseStorm ThreatMatch feed.
Continuous research is being conducted for all newly discovered or recurring malware and ransomware. As always, DefenseStorm recommends the following practices to help secure your environment:
Desrah Kraft
Cyber Threat Intelligence Engineer
Desrah Kraft is a Cyber Threat Intelligence Engineer at DefenseStorm. For the past three years, she has played a vital role in leading and contributing to various Incident Response efforts. Before transitioning into cybersecurity, Desrah obtained a bachelor’s degree from Mitchell College and worked for 7 years in law enforcement. This experience helped her cultivate a comprehensive understanding of security principles and investigative practices. An accomplished cybersecurity professional with 4 years of hands-on experience in analyzing malware and extensive expertise in safeguarding digital landscapes against malicious threats, Desrah possesses an unparalleled ability to dissect complex cyber threats, identify their origins, and implement effective countermeasures. Additionally, she holds multiple MITRE certifications, which demonstrate her mastery of advanced threat detection and mitigation techniques. Recognized for her keen eye for anomalies and proactive approach, Desrah excels in Endpoint Detection and Response (EDR), enabling rapid identification, investigation, and containment of potential breaches. Committed to continuous growth and learning, Desrah remains at the forefront of cybersecurity, dedicated to fortifying digital infrastructures and inspiring others in the field.
