Detection rules › Splunk

Windows Modify Registry Default Icon Setting

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects suspicious modifications to the Windows registry's default icon settings, a technique associated with Lockbit ransomware. It leverages data from the Endpoint Registry data model, focusing on changes to registry paths under "HKCR\\defaultIcon\(Default)*". This activity is significant as it is uncommon for normal users to modify these settings, and such changes can indicate ransomware infection or other malware. If confirmed malicious, this could lead to system defacement and signal a broader ransomware attack, potentially compromising sensitive data and system integrity.

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="*HKCR\\*" Registry.registry_path="*\\defaultIcon\\(Default)*" 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: search

search

Stage 4: search

search

Stage 5: 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
  • "*HKCR\\*"
  • "*\\defaultIcon\\(Default)*"