Detection rules › Splunk

Windows Modify Registry NoChangingWallPaper

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects modifications to the Windows registry aimed at preventing wallpaper changes. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the "NoChangingWallPaper" registry value. This activity is significant as it is a known tactic used by Rhysida ransomware to enforce a malicious wallpaper, thereby limiting user control over system settings. If confirmed malicious, this registry change could indicate a ransomware infection, leading to further system compromise and user disruption.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1112 Modify Registry
Defense EvasionT1112 Modify Registry

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE Registry.registry_path="*\\Windows\\CurrentVersion\\Policies\\ActiveDesktop\\NoChangingWallPaper" Registry.registry_value_data=1 BY Registry.action, Registry.dest, Registry.process_guid, Registry.process_id, Registry.registry_hive, Registry.registry_path, Registry.registry_key_name, Registry.registry_value_data, Registry.registry_value_name, Registry.registry_value_type, Registry.status, Registry.user, Registry.vendor_product

Stage 2: search

search

Stage 3: where

where isnotnull(registry_value_data)

Stage 4: search

search

Stage 5: search

search

Stage 6: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Registry.registry_patheq
  • "*\\Windows\\CurrentVersion\\Policies\\ActiveDesktop\\NoChangingWallPaper"
Registry.registry_value_dataeq
  • 1 corpus 2 (splunk 2)