Detection rules › Splunk

Windows Impair Defense Disable Win Defender Scan On Update

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects modifications to the Windows registry that disable the Windows Defender Scan On Update feature. It leverages data from the Endpoint.Registry datamodel, specifically looking for changes to the "DisableScanOnUpdate" registry setting with a value of "0x00000001". This activity is significant because disabling automatic scans can leave systems vulnerable to malware and other threats. If confirmed malicious, this action could allow attackers to bypass Windows Defender, facilitating further compromise and persistence within the environment.

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="*\\Windows Defender\\Signature Updates\\DisableScanOnUpdate" Registry.registry_value_data="0x00000001" 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
  • "*\\Windows Defender\\Signature Updates\\DisableScanOnUpdate"
Registry.registry_value_dataeq
  • "0x00000001" corpus 42 (splunk 42)