The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify the execution of the
Get-DomainUser commandlet with specific parameters.
Get-DomainUser is part of PowerView, a PowerShell tool used to perform enumeration on Windows Active Directory networks. As the name suggests,
Get-DomainUser is used to identify domain users and combining it with
-PreauthNotRequired allows adversaries to discover domain accounts with Kerberos Pre Authentication disabled.\ Red Teams and adversaries alike use may leverage PowerView to enumerate these accounts and attempt to crack their passwords offline.
- Type: TTP
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-05-03
- Author: Mauricio Velazco, Splunk
- ID: b0b34e2c-90de-11ec-baeb-acde48001122
Kill Chain Phase
- CIS 10
1 2 3 4 5 `powershell` EventCode=4104 (ScriptBlockText = "*Get-DomainUser*" AND ScriptBlockText="*PreauthNotRequired*") | stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText | rename Computer as dest | `security_content_ctime(firstTime)` | `disabled_kerberos_pre_authentication_discovery_with_powerview_filter`
The SPL above uses the following Macros:
disabled_kerberos_pre-authentication_discovery_with_powerview_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
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/18.104.22.168/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
Administrators or power users may use PowerView for troubleshooting
Associated Analytic Story
|54.0||60||90||Disabled Kerberos Pre-Authentication Discovery With PowerView from $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 2