User Added To Admin Group Via Sysadminctl — Sigma Rule

Rule metadata and linked tags

Author: Sohan G (D4rkCiph3r). Source status: test; severity: medium. Source dates: 2023-03-19 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b83edb6ae7fc5f353b7f503bd19de7c64b342e9690a06e4b410a711bb71f2c62

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 Added To Admin Group Via Sysadminctl
id: 652c098d-dc11-4ba6-8566-c20e89042f2b
related:
    - id: 0c1ffcf9-efa9-436e-ab68-23a9496ebf5b
      type: obsolete
status: test
description: Detects attempts to create and add an account to the admin group via "sysadminctl"
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1078.003/T1078.003.md#atomic-test-3---create-local-account-with-admin-privileges-using-sysadminctl-utility---macos
    - https://ss64.com/osx/sysadminctl.html
author: Sohan G (D4rkCiph3r)
date: 2023-03-19
tags:
    - attack.persistence
    - attack.initial-access
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1078.003
logsource:
    category: process_creation
    product: macos
detection:
    selection:
        # Creates and adds new user to admin group
        Image|endswith: '/sysadminctl'
        CommandLine|contains|all:
            - ' -addUser '
            - ' -admin '
    condition: selection
falsepositives:
    - Legitimate administration activities
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate administration activities

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1078.003/T1078.003.md#atomic-test-3---create-local-account-with-admin-privileges-using-sysadminctl-utility---macos
• https://ss64.com/osx/sysadminctl.html