---
title: "Disabled Kerberos Pre-Authentication Discovery With PowerView"
excerpt: "Steal or Forge Kerberos Tickets, AS-REP Roasting"
categories:
  - Endpoint
last_modified_at: 2022-02-18
toc: true
toc_label: ""
tags:
  - Steal or Forge Kerberos Tickets
  - Credential Access
  - AS-REP Roasting
  - Credential Access
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
---



[Try in Splunk Security Cloud](https://www.splunk.com/en_us/cyber-security.html){: .btn .btn--success}

#### 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](https://github.com/splunk/security_content/wiki/Detection-Analytic-Types)
- **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- **Datamodel**: 
- **Last Updated**: 2022-02-18
- **Author**: Mauricio Velazco, Splunk
- **ID**: b0b34e2c-90de-11ec-baeb-acde48001122


#### [ATT&CK](https://attack.mitre.org/)

| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1558](https://attack.mitre.org/techniques/T1558/) | Steal or Forge Kerberos Tickets | Credential Access |

| [T1558.004](https://attack.mitre.org/techniques/T1558/004/) | AS-REP Roasting | Credential Access |

#### Search

```
 `powershell` EventCode=4104 (Message = "*Get-DomainUser*" AND Message="*PreauthNotRequired*") 
| stats count min(_time)  as firstTime max(_time) as lastTime by EventCode Message ComputerName User 
| `security_content_ctime(firstTime)` 
| `disabled_kerberos_pre_authentication_discovery_with_powerview_filter`
```

#### Macros
The SPL above uses the following Macros:
* [powershell](https://github.com/splunk/security_content/blob/develop/macros/powershell.yml)
* [security_content_ctime](https://github.com/splunk/security_content/blob/develop/macros/security_content_ctime.yml)

Note that `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 field
* _time
* EventCode
* Message
* ComputerName
* User


#### 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
* [Active Directory Kerberos Attacks](/stories/active_directory_kerberos_attacks)


#### Kill Chain Phase
* Privilege Escalation



#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 54.0 | 60 | 90 | Disabled Kerberos Pre-Authentication Discovery With PowerView from $dest$ |


Note that risk score is calculated base on the following formula: `(Impact * Confidence)/100`



#### Reference

* [https://attack.mitre.org/techniques/T1558/004/](https://attack.mitre.org/techniques/T1558/004/)
* [https://m0chan.github.io/2019/07/31/How-To-Attack-Kerberos-101.html](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/](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`](https://github.com/splunk/attack_data#using-replaypy) tool or the [UI](https://github.com/splunk/attack_data#using-ui).
Alternatively you can replay a dataset into a [Splunk Attack Range](https://github.com/splunk/attack_range#replay-dumps-into-attack-range-splunk-server)

* [https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1558.004/powerview/windows-powershell.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1558.004/powerview/windows-powershell.log)



[*source*](https://github.com/splunk/security_content/tree/develop/detections/endpoint/disabled_kerberos_pre-authentication_discovery_with_powerview.yml) \| *version*: **1**