Sigma rule: REvil Kaseya Incident Malware Patterns

Rule

Title

REvil Kaseya Incident Malware Patterns

Status

test

Level

critical

Author

Florian Roth (Nextron Systems)

Date

2021-07-03

Modified

2022-05-20

File

rules-emerging-threats/2021/TA/Kaseya-Supply-Chain/proc_creation_win_apt_revil_kaseya.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects process command line patterns and locations used by REvil group in Kaseya incident (can also match on other malware)

Log source

product

windows

category

process_creation

Detection

selection1:
    CommandLine|contains:
        - 'C:\Windows\cert.exe'
        - 'del /q /f c:\kworking\agent.crt'
        - 'Kaseya VSA Agent Hot-fix'
        - '\AppData\Local\Temp\MsMpEng.exe'
        - 'rmdir /s /q %SystemDrive%\inetpub\logs'
        - 'del /s /q /f %SystemDrive%\\*.log'
        - 'c:\kworking1\agent.exe'
        - 'c:\kworking1\agent.crt'
selection2:
    Image:
        - 'C:\Windows\MsMpEng.exe'
        - 'C:\Windows\cert.exe'
        - 'C:\kworking\agent.exe'
        - 'C:\kworking1\agent.exe'
selection3:
    CommandLine|contains|all:
        - 'del /s /q /f'
        - 'WebPages\Errors\webErrorLog.txt'
condition: 1 of selection*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.t1059
• attack.g0115
• detection.emerging-threats

MITRE ATT&CK ids this rule names

• G0115
• T1059

References

• https://community.sophos.com/b/security-blog/posts/active-ransomware-attack-on-kaseya-customers
• https://www.joesandbox.com/analysis/443736/0/html
• https://doublepulsar.com/kaseya-supply-chain-attack-delivers-mass-ransomware-event-to-us-companies-76e4ec6ec64b
• https://therecord.media/revil-ransomware-executes-supply-chain-attack-via-malicious-kaseya-update/
• https://blog.truesec.com/2021/07/04/kaseya-supply-chain-attack-targeting-msps-to-deliver-revil-ransomware/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/TA/Kaseya-Supply-Chain/proc_creation_win_apt_revil_kaseya.yml