administrators or power users may use search for accounts with kerberos pre authentication disabled for legitimate purposes.

Techniques

T1558.004

Sample rules

Disabled Kerberos Pre-Authentication Discovery With Get-ADUser

source: splunk
technicques:
- T1558.004

Description

The following analytic detects the execution of the Get-ADUser PowerShell cmdlet with parameters indicating a search for domain accounts with Kerberos Pre-Authentication disabled. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this specific activity. This behavior is significant because discovering accounts with Kerberos Pre-Authentication disabled can allow adversaries to perform offline password cracking. If confirmed malicious, this activity could lead to unauthorized access to user accounts, potentially compromising sensitive information and escalating privileges within the network.

Detection logic

`powershell` EventCode=4104 (ScriptBlockText = "*Get-ADUser*" AND ScriptBlockText="*4194304*") 
| 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)` 
| `security_content_ctime(lastTime)` 
| `disabled_kerberos_pre_authentication_discovery_with_get_aduser_filter`