Linux Setuid Capability Set on a Binary via Setcap Utility

Title: Linux Setuid Capability Set on a Binary via Setcap Utility
Status: experimental
Description:Detects the use of the 'setcap' utility to set the 'setuid' capability (cap_setuid) on a binary file. This capability allows a non privileged process to make arbitrary manipulations of user IDs (UIDs), including setting its current UID to a value that would otherwise be restricted (i.e. UID 0, the root user). This behavior can be used by adversaries to backdoor a binary in order to escalate privileges again in the future if needed.
References:
  -https://man7.org/linux/man-pages/man8/setcap.8.html
  -https://dfir.ch/posts/linux_capabilities/
  -https://juggernaut-sec.com/capabilities/#cap_setuid
Author: Luc Génaux
Date: 2026-01-24
modified:None
Tags:

• -'attack.privilege-escalation'
• -'attack.defense-evasion'
• -'attack.persistence'
• -'attack.t1548'
• -'attack.t1554'

Logsource:

• product: linux
• category: process_creation

Detection:
  selection:
    Image|endswith: '/setcap'
    CommandLine|contains: 'cap_setuid'
  condition:selection
Falsepositives:
  -Unknown
Level: low