GetAdComputer with PowerShell Script Block

 Original Source: [splunk source]
Name:GetAdComputer with PowerShell Script Block
id:a9a1da02-8e27-4bf7-a348-f4389c9da487
version:11
date:None
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*")

| fillnull

| stats count min(_time) as firstTime max(_time) as lastTime
BY dest signature signature_id
user_id vendor_product EventID
Guid Opcode Name
Path ProcessID ScriptBlockId
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://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
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
drilldown_searches:
  :
analytic_story:['Active Directory Discovery', 'CISA AA22-320A', 'Medusa Ransomware', 'Gozi Malware']

asset_type:Endpoint

mitre_attack_id:['T1018']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:endpoint

security_domain:endpoint

tags:

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
 test_type:'unit'
manual_test:None