Get ADUser with PowerShell Script Block
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.
- Type: Hunting
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-09-13
- Author: Teoderick Contreras, Mauricio Velazco, Splunk
- ID: 21432e40-04f4-11ec-b7e6-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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`powershell` EventCode=4104 ScriptBlockText = "*get-aduser*" ScriptBlockText = "*-filter*"
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID
| rename Computer as dest, UserID as user
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `get_aduser_with_powershell_script_block_filter`
Macros
The SPL above uses the following Macros:
get_aduser_with_powershell_script_block_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- EventCode
- Message
- ComputerName
- User
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.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
25.0 | 50 | 50 | Powershell process having commandline "get-aduser" for user enumeration on $dest$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- 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
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 2