Detection rules › Sigma
Access of Sudoers File Content
Detects the execution of a text-based file access or inspection utilities to read the content of /etc/sudoers in order to potentially list all users that have sudo rights.
Known false positives
- Legitimate administration activities
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Reconnaissance |
Telemetry coverage
| Platform | Record / event type |
|---|---|
| Linux | Event ID 1: Process Create |
Rule body
title: Access of Sudoers File Content
id: 0f79c4d2-4e1f-4683-9c36-b5469a665e06
status: test
description: Detects the execution of a text-based file access or inspection utilities to read the content of /etc/sudoers in order to potentially list all users that have sudo rights.
references:
- https://github.com/sleventyeleven/linuxprivchecker/
author: Florian Roth (Nextron Systems)
date: 2022-06-20
modified: 2025-06-04
tags:
- attack.reconnaissance
- attack.t1592.004
logsource:
category: process_creation
product: linux
detection:
selection:
Image|endswith:
- '/cat'
- '/ed'
- '/egrep'
- '/emacs'
- '/fgrep'
- '/grep'
- '/head'
- '/less'
- '/more'
- '/nano'
- '/tail'
CommandLine|contains: ' /etc/sudoers'
condition: selection
falsepositives:
- Legitimate administration activities
level: medium
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith:
- '/cat'
- '/ed'
- '/egrep'
- '/emacs'
- '/fgrep'
- '/grep'
- '/head'
- '/less'
- '/more'
- '/nano'
- '/tail'
CommandLine|contains: ' /etc/sudoers'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match value:" /etc/sudoers" |
Image | ends_with |
| field:"Image" kind:ends_with |