Detection rules › Splunk
Windows Impair Defense Define Win Defender Threat Action
The following analytic detects modifications to the Windows Defender ThreatSeverityDefaultAction registry setting. It leverages data from the Endpoint.Registry datamodel to identify changes in registry values that define how Windows Defender responds to threats. This activity is significant because altering these settings can impair the system's defense mechanisms, potentially allowing threats to go unaddressed. If confirmed malicious, this could enable attackers to bypass antivirus protections, leading to persistent threats and increased risk of data compromise or further system exploitation.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Evasion | T1562.001 Impair Defenses: Disable or Modify Tools |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 13 | RegistryEvent (Value Set) |
Stages and Predicates
Stage 1: tstats
tstats WHERE Registry.registry_path="*\\Windows Defender\\Threats\\ThreatSeverityDefaultAction*" Registry.registry_value_data IN ("0x00000001", "9") 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.
| Field | Kind | Values |
|---|---|---|
Registry.registry_path | eq |
|
Registry.registry_value_data | in |
|