Detection rules › Splunk

Windows Impair Defense Configure App Install Control

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects modifications to the Windows registry that disable the Windows Defender SmartScreen App Install Control feature. It leverages data from the Endpoint.Registry data model to identify changes to specific registry values. This activity is significant because disabling App Install Control can allow users to install potentially malicious web-based applications without restrictions, increasing the risk of security vulnerabilities. If confirmed malicious, this action could lead to the installation of harmful applications, potentially compromising the system and exposing sensitive information.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1562.001 Impair Defenses: Disable or Modify Tools

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE ((Registry.registry_path="*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControlEnabled" Registry.registry_value_data="0x00000000") OR (Registry.registry_path="*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControl" Registry.registry_value_data="Anywhere")) 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
  • "*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControl"
  • "*\\Microsoft\\Windows Defender\\SmartScreen\\ConfigureAppInstallControlEnabled"
Registry.registry_value_dataeq
  • "0x00000000" corpus 27 (splunk 27)
  • "Anywhere"