Detection: Windows PowerShell Disabled Kerberos Pre-Authentication Discovery With PowerView
Description
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.
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Implementation
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 PowerView for troubleshooting
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Disabled Kerberos Pre-Authentication Discovery With PowerView from $dest_device_id$ | 54 | 60 | 90 |
References
-
https://m0chan.github.io/2019/07/31/How-To-Attack-Kerberos-101.html
-
https://stealthbits.com/blog/cracking-active-directory-passwords-with-as-rep-roasting/
Version: 4