1200KM / sigma-rule
User Has Been Deleted Via Userdel — Sigma Rule
Sigma rule 08f26069-6f80-474b-8d1f-d971c6fedea0. User Has Been Deleted Via Userdel — Sigma Rule. Detects execution of the "userdel" binary. Which is used to delete a user account and related files. This is sometimes abused by threat actors in order to cover their tracks
Rule metadata and linked tags
Author: Tuan Le (NCSGroup). Source status: test; severity: medium. Source dates: 2022-12-26 / not supplied.
{
"product": "linux",
"category": "process_creation"
}Pinned original Sigma rule · Detection Rule License 1.1
Source SHA-256: 9e496bef69fe6c2932295d13c9a5d9778f5bb86eb7e733b81cf1da41803a2225
Detection logic
Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.
title: User Has Been Deleted Via Userdel
id: 08f26069-6f80-474b-8d1f-d971c6fedea0
status: test
description: Detects execution of the "userdel" binary. Which is used to delete a user account and related files. This is sometimes abused by threat actors in order to cover their tracks
references:
- https://linuxize.com/post/how-to-delete-group-in-linux/
- https://www.cyberciti.biz/faq/linux-remove-user-command/
- https://www.cybrary.it/blog/0p3n/linux-commands-used-attackers/
- https://linux.die.net/man/8/userdel
author: Tuan Le (NCSGroup)
date: 2022-12-26
tags:
- attack.impact
- attack.t1531
logsource:
product: linux
category: process_creation
detection:
selection:
Image|endswith: '/userdel'
condition: selection
falsepositives:
- Legitimate administrator activities
level: medium
False positives
- Legitimate administrator activities
Source references
Connected ecosystem references
Exact source-tagged techniques
Telemetry review
Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.
Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.