Local System Accounts Discovery - MacOs

SIGMA detection rule by Alejandro Ortuno, oscd.community · NOASSERTION

Detects enumeration of local system accounts on MacOS systems. This can be used by attackers to identify accounts for lateral movement or privilege escalation.

title: Local System Accounts Discovery - MacOs
id: ddf36b67-e872-4507-ab2e-46bda21b842c
status: test
description: |
    Detects enumeration of local system accounts on MacOS systems.
    This can be used by attackers to identify accounts for lateral movement or privilege escalation.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1087.001/T1087.001.md
    - https://ss64.com/osx/dscl.html
    - https://ss64.com/mac/dscacheutil.html
author: Alejandro Ortuno, oscd.community
date: 2020-10-08
modified: 2026-07-07
tags:
    - attack.discovery
    - attack.t1087.001
logsource:
    category: process_creation
    product: macos
detection:
    selection_dscl:
        Image|endswith: '/dscl'
        CommandLine|contains|all:
            - 'list'
            - '/users'
    selection_dscacheutil:
        Image|endswith: '/dscacheutil'
        CommandLine|contains|all:
            - '-q'
            - 'user'
    selection_root:
        CommandLine|contains: '''*:0:'''
    selection_passwd_sudo:
        Image|endswith:
            - '/cat'
            - '/awk'
            - '/grep'
        CommandLine|contains:
            - '/etc/passwd'
            - '/etc/sudoers'
    selection_id:
        Image|endswith: '/id'
    selection_lsof:
        Image|endswith: '/lsof'
        CommandLine|contains: '-u'
    selection_logged_in_users:
        Image|endswith:
            - '/who'
            - '/w'
            - '/users'
            - '/last'
    selection_home_dir_listing:
        Image|endswith: '/ls'
        CommandLine|endswith:
            - '/Users'
            - "/Users'"
            - '/Users"'
    selection_loginwindow_prefs:
        Image|endswith:
            - '/defaults' # defaults read /Library/Preferences/com.apple.loginwindow
            - '/plutil' # plutil -p /Library/Preferences/com.apple.loginwindow.plist
        CommandLine|contains: 'com.apple.loginwindow'
    condition: 1 of selection*
falsepositives:
    - Legitimate administration activities
level: low

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a81dc39f-8062-4b81-9707-51574bd99cee

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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Format & documentation suggestions

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