Local System Accounts Discovery - MacOs — Sigma Rule

Rule metadata and linked tags

Author: Alejandro Ortuno, oscd.community. Source status: test; severity: low. Source dates: 2020-10-08 / 2022-11-27.

{
  "category": "process_creation",
  "product": "macos"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 05f99670aeab20412eabe48e44d73e3b0dc2bbc109e704cf4b80f9b368b105ce

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: Local System Accounts Discovery - MacOs
id: ddf36b67-e872-4507-ab2e-46bda21b842c
status: test
description: Detects enumeration of local systeam accounts on MacOS
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1087.001/T1087.001.md
author: Alejandro Ortuno, oscd.community
date: 2020-10-08
modified: 2022-11-27
tags:
    - attack.discovery
    - attack.t1087.001
logsource:
    category: process_creation
    product: macos
detection:
    selection_1:
        Image|endswith: '/dscl'
        CommandLine|contains|all:
            - 'list'
            - '/users'
    selection_2:
        Image|endswith: '/dscacheutil'
        CommandLine|contains|all:
            - '-q'
            - 'user'
    selection_3:
        CommandLine|contains: '''x:0:'''
    selection_4:
        Image|endswith: '/cat'
        CommandLine|contains:
            - '/etc/passwd'
            - '/etc/sudoers'
    selection_5:
        Image|endswith: '/id'
    selection_6:
        Image|endswith: '/lsof'
        CommandLine|contains: '-u'
    condition: 1 of selection*
falsepositives:
    - Legitimate administration activities
level: low

Original YAML and metadata in JSON

False positives

• Legitimate administration activities

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1087.001/T1087.001.md