Detection rules › Sigma
User Has Been Deleted Via Userdel
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
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Impact | T1531 Account Access Removal |
Event coverage
| Provider | Event |
|---|---|
| Sysmon-for-Linux | Event ID 1 |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '/userdel'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|