Windows Disable Windows Group Policy Features Through Registry

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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.

• Type: Anomaly
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2024-05-27
• Author: Steven Dick, Teoderick Contreras, Splunk
• ID: 63a449ae-9f04-11ec-945e-acde48001122

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1112	Modify Registry	Defense Evasion

Kill Chain Phase

• Exploitation

NIST

• DE.AE

CIS20

• CIS 10

CVE

Search

| 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 
| `drop_dm_object_name(Registry)` 
| where isnotnull(registry_value_data) 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_disable_windows_group_policy_features_through_registry_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• security_content_summariesonly

windows_disable_windows_group_policy_features_through_registry_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
• Registry.dest
• Registry.registry_value_name
• Registry.registry_key_name
• Registry.registry_path
• Registry.registry_value_data
• Registry.process_guid

How To Implement

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

• Ransomware
• CISA AA23-347A
• Windows Defense Evasion Tactics
• Windows Registry Abuse

RBA

Risk Score	Impact	Confidence	Message
49.0	70	70	Registry modification to disable windows group policy features on $dest$

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://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

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: 5