Sigma rule: Linux Setgid Capability Set on a Binary via Setcap Utility

Rule

Title

Linux Setgid Capability Set on a Binary via Setcap Utility

Status

experimental

Level

low

Author

Luc Génaux

Date

2026-01-24

File

rules/linux/process_creation/proc_creation_lnx_cap_setgid.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the use of the 'setcap' utility to set the 'setgid' capability (cap_setgid) on a binary file.
This capability allows a non privileged process to make arbitrary manipulations of group IDs (GIDs), including setting its current GID to a value that would otherwise be restricted (i.e. GID 0, the root group).
This behavior can be used by adversaries to backdoor a binary in order to escalate privileges again in the future if needed.

Log source

product

linux

category

process_creation

Detection

selection:
    Image|endswith: '/setcap'
    CommandLine|contains: 'cap_setgid'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.persistence
• attack.t1548
• attack.t1554

MITRE ATT&CK ids this rule names

• T1548
• T1554

References

• https://man7.org/linux/man-pages/man8/setcap.8.html
• https://dfir.ch/posts/linux_capabilities/
• https://juggernaut-sec.com/capabilities/#cap_setgid

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/process_creation/proc_creation_lnx_cap_setgid.yml