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.
- 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
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`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`
Macros
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.
Required fields
List of fields required to use this analytic.
- _time
- ScriptBlockText
- Opcode
- Computer
- UserID
- EventCode
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/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
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
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.
Reference
- https://attack.mitre.org/techniques/T1558/004/
- 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/
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