Suspicious XZ Utils Backdoor Kill-Switch Environment String via process_creation
- Product
- linux
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-07-30
- Updated
- 2026-08-28
ATT&CK techniques
Initial Access → Cred AccessRecon
Resource Dev
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects the hardcoded kill-switch string used by the XZ Utils liblzma backdoor (CVE-2024-3094) appearing in process command lines or environment variables. The backdoor checks for this specific token to disable itself, and its presence in telemetry indicates interaction with the implanted malicious code. Investigating hosts exhibiting this string helps identify systems affected by the supply chain attack.
Reporting behind it
- elastic.cohttps://www.elastic.co/security-labs/500ms-to-midnight
- attack.mitre.orghttps://attack.mitre.org/techniques/T1556/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1059/004/
- securelist.comhttps://securelist.com/xz-backdoor-story-part-1/112354/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1195/001/
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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