GetAdComputer with PowerShell Script Block
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.
Query · spl
`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`
Implementation guide
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.
Analyst notes
Known false positives: Administrators or power users may use this PowerShell commandlet for troubleshooting.