name: GetAdComputer with PowerShell Script Block
id: a9a1da02-8e27-4bf7-a348-f4389c9da487
version: 5
date: '2024-10-17'
author: Mauricio Velazco, Splunk
status: production
type: Hunting
description: The following analytic detects the execution of the `Get-AdComputer` PowerShell commandlet using PowerShell Script Block Logging (EventCode=4104). This detection leverages script block text to identify when this commandlet is run. The `Get-AdComputer` commandlet is significant as it can be used by adversaries to enumerate all domain computers, aiding in situational awareness and Active Directory discovery. If confirmed malicious, this activity could allow attackers to map the network, identify targets, and plan further attacks, potentially leading to unauthorized access and data exfiltration.
data_source:
- Powershell Script Block Logging 4104
search: '`powershell` EventCode=4104 (ScriptBlockText = "*Get-AdComputer*") | stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText | `security_content_ctime(firstTime)` | `getadcomputer_with_powershell_script_block_filter`'
how_to_implement: To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
known_false_positives: Administrators or power users may use this PowerShell commandlet for troubleshooting.
references:
- https://attack.mitre.org/techniques/T1018/
- https://docs.microsoft.com/en-us/powershell/module/activedirectory/get-adgroup?view=windowsserver2019-ps
tags:
  analytic_story:
  - Active Directory Discovery
  - CISA AA22-320A
  - Gozi Malware
  asset_type: Endpoint
  confidence: 50
  impact: 30
  message: Remote system discovery enumeration on $Computer$ by $UserID$
  mitre_attack_id:
  - T1018
  observable:
  - name: Computer
    type: Endpoint
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - ScriptBlockText
  - Opcode
  - Computer
  - UserID
  - EventCode
  risk_score: 15
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/powershell_script_block_logging/sbl_xml.log
    source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
    sourcetype: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational