Detection: Windows Disable Windows Group Policy Features Through Registry

Description

The following analytic detects suspicious registry modifications aimed at disabling Windows Group Policy features. It leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values associated with disabling key Windows functionalities. This activity is significant because it is commonly used by ransomware to hinder mitigation and forensic response efforts. If confirmed malicious, this behavior could severely impair the ability of security teams to analyze and respond to the attack, allowing the attacker to maintain control and persist within the compromised environment.

Search

1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\*" OR Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\*" Registry.registry_value_name IN ("NoDesktop", "NoFind", "NoControlPanel", "NoFileMenu", "NoSetTaskbar", "NoTrayContextMenu", "TaskbarLockAll", "NoThemesTab","NoPropertiesMyDocuments","NoVisualStyleChoice","NoColorChoice","NoPropertiesMyDocuments") Registry.registry_value_data = "0x00000001") BY _time span=1h Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid 
3| `drop_dm_object_name(Registry)` 
4| where isnotnull(registry_value_data) 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `windows_disable_windows_group_policy_features_through_registry_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 12	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'	N/A

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the offical Sysmon TA. https://splunkbase.splunk.com/app/5709

Known False Positives

Disabling these features for legitimate purposes is not a common use case but can still be implemented by the administrators. Filter as needed.

Associated Analytic Story

• CISA AA23-347A

• Ransomware

• Windows Defense Evasion Tactics

• Windows Registry Abuse

Risk Based Analytics (RBA)

References

• https://hybrid-analysis.com/sample/ef1c427394c205580576d18ba68d5911089c7da0386f19d1ca126929d3e671ab?environmentId=120&lang=en

• https://www.sophos.com/en-us/threat-center/threat-analyses/viruses-and-spyware/Troj~Krotten-N/detailed-analysis

• https://www.virustotal.com/gui/file/2d7855bf6470aa323edf2949b54ce2a04d9e38770f1322c3d0420c2303178d91/details

Detection Testing

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: GitHub | Version: 5