---
title: "GetAdComputer with PowerShell Script Block"
excerpt: "Remote System Discovery
"
categories:
  - Endpoint
last_modified_at: 2021-09-01
toc: true
toc_label: ""
tags:
  - Remote System Discovery
  - Discovery
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
---



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

#### Description

The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify the execution of the `Get-AdGroup` commandlet. The `Get-AdGroup` commandlet is used to return a list of all domain computers. Red Teams and adversaries may leverage this commandlet to enumerate domain computers for situational awareness and Active Directory Discovery.

- **Type**: [Hunting](https://github.com/splunk/security_content/wiki/Detection-Analytic-Types)
- **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

- **Last Updated**: 2021-09-01
- **Author**: Mauricio Velazco, Splunk
- **ID**: a9a1da02-8e27-4bf7-a348-f4389c9da487


#### Annotations

<details>
  <summary>ATT&CK</summary>

<div markdown="1">


| ID             | Technique        |  Tactic             |
| -------------- | ---------------- |-------------------- |
| [T1018](https://attack.mitre.org/techniques/T1018/) | Remote System Discovery | Discovery |

</div>
</details>


<details>
  <summary>Kill Chain Phase</summary>

<div markdown="1">

* Reconnaissance


</div>
</details>


<details>
  <summary>NIST</summary>

<div markdown="1">



</div>
</details>

<details>
  <summary>CIS20</summary>

<div markdown="1">



</div>
</details>

<details>
  <summary>CVE</summary>

<div markdown="1">


</div>
</details>

#### Search 

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

> :information_source:
> **getadcomputer_with_powershell_script_block_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 this PowerShell commandlet for troubleshooting.

#### Associated Analytic story
* [Active Directory Discovery](/stories/active_directory_discovery)




#### RBA

| Risk Score  | Impact      | Confidence   | Message      |
| ----------- | ----------- |--------------|--------------|
| 15.0 | 30 | 50 | Remote system discovery enumeration on $dest$ by $user$ |


> :information_source:
> 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/T1018/](https://attack.mitre.org/techniques/T1018/)
* [https://docs.microsoft.com/en-us/powershell/module/activedirectory/get-adgroup?view=windowsserver2019-ps](https://docs.microsoft.com/en-us/powershell/module/activedirectory/get-adgroup?view=windowsserver2019-ps)



#### 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/T1018/AD_discovery/windows-powershell.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1018/AD_discovery/windows-powershell.log)



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