This analytic is to detect a suspicious registry modification to disable windows features. These techniques are seen in several ransomware malware to impair the compromised host to make it hard for analyst to mitigate or response from the attack. Disabling these known features make the analysis and forensic response more hard. Disabling these feature is not so common but can still be implemented by the administrator for security purposes. In this scenario filters for users that are allowed doing this is needed.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2023-04-27
- Author: Steven Dick, Teoderick Contreras, Splunk
- ID: 63a449ae-9f04-11ec-945e-acde48001122
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 7 | 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`
The SPL above uses the following Macros:
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.
List of fields required to use this analytic.
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
|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.
source | version: 4