Remove Account From Domain Admin Group

Status: test
Severity: medium
Log source: category ps_script, product windows
Author: frack113
Source: github.com/SigmaHQ/sigma

Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users. Accounts may be deleted, locked, or manipulated (ex: changed credentials) to remove access to accounts.

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1531` Account Access Removal

Telemetry coverage

Provider	Record / event type
PowerShell	Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal).

Rule body

title: Remove Account From Domain Admin Group
id: 48a45d45-8112-416b-8a67-46e03a4b2107
status: test
description: |
    Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users.
    Accounts may be deleted, locked, or manipulated (ex: changed credentials) to remove access to accounts.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1531/T1531.md#atomic-test-3---remove-account-from-domain-admin-group
author: frack113
date: 2021-12-26
tags:
    - attack.impact
    - attack.t1531
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'Remove-ADGroupMember'
            - '-Identity '
            - '-Members '
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    ScriptBlockText|contains|all:
        - 'Remove-ADGroupMember'
        - '-Identity '
        - '-Members '

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`ScriptBlockText`	match	`-Identity` `-Members` `Remove-ADGroupMember`	`field:"ScriptBlockText" kind:match`