name: Get ADUser with PowerShell Script Block
id: 21432e40-04f4-11ec-b7e6-acde48001122
version: 1
date: '2021-08-24'
author: Teoderick Contreras, Mauricio Velazco, Splunk
type: Hunting
datamodel: []
description: The following analytic utilizes PowerShell Script Block Logging (EventCode=4104)
  to identify the execution of the `Get-AdGUser` commandlet. The `Get-AdUser` commandlet
  is used to return a list of all domain users. Red Teams and adversaries may leverage
  this commandlet to enumerate domain groups for situational awareness and Active
  Directory Discovery.
search: '`powershell` EventCode=4104 Message = "*get-aduser*" Message = "*-filter*"
  | stats count min(_time) as firstTime max(_time) as lastTime by EventCode Message
  ComputerName User | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
  | `get_aduser_with_powershell_script_block_filter`'
how_to_implement: The following Hunting analytic requires PowerShell operational logs
  to be imported. Modify the powershell macro as needed to match the sourcetype or
  add index. This analytic is specific to 4104, or PowerShell Script Block Logging.
known_false_positives: Administrators or power users may use this command for troubleshooting.
references:
- https://www.blackhillsinfosec.com/red-blue-purple/
- https://attack.mitre.org/techniques/T1087/002/
- https://docs.microsoft.com/en-us/powershell/module/activedirectory/get-aduser?view=windowsserver2019-ps
tags:
  analytic_story:
  - Active Directory Discovery
  confidence: 50
  context:
  - Source:Endpoint
  - Stage:Discovery
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.002/AD_discovery/windows-powershell.log
  impact: 50
  kill_chain_phases:
  - Reconnaissance
  message: powershell process having commandline $Message$ for user enumeration
  mitre_attack_id:
  - T1087.002
  - T1087
  observable:
  - name: ComputerName
    type: Hostname
    role:
    - Victim
  - name: User
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - EventCode
  - Message
  - ComputerName
  - User
  risk_score: 25
  security_domain: endpoint
  asset_type: Endpoint