name: GetLocalUser with PowerShell Script Block
id: 2e891cbe-0426-11ec-9c9c-acde48001122
version: 2
date: '2022-03-22'
author: Mauricio Velazco, Splunk
type: Hunting
datamodel: []
description: The following analytic utilizes PowerShell Script Block Logging (EventCode=4104)
  to identify the execution of the `Get-LocalUser` commandlet. The `Get-LocalUser`
  commandlet is used to return a list of all local users. Red Teams and adversaries
  may leverage this commandlet to enumerate users for situational awareness and Active
  Directory Discovery.
search: '`powershell` EventCode=4104 (ScriptBlockText = "*Get-LocalUser*") 
  | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer user_id 
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `getlocaluser_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/T1087/001/
- https://www.splunk.com/en_us/blog/security/hunting-for-malicious-powershell-using-script-block-logging.html
tags:
  analytic_story:
  - Active Directory Discovery
  - Malicious PowerShell
  confidence: 50
  context:
  - Source:Endpoint
  - Stage:Discovery
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.001/AD_discovery/windows-powershell-xml.log
  impact: 30
  kill_chain_phases:
  - Reconnaissance
  message: Local user discovery enumeration using PowerShell on $Computer$ by $user$
  mitre_attack_id:
  - T1087
  - T1087.001
  - T1059.001
  observable:
  - name: Computer
    type: Endpoint
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - EventCode 
  - ScriptBlockText
  - Computer
  - UserID
  risk_score: 15
  security_domain: endpoint
  asset_type: Endpoint