Detection rules › Splunk

Windows Registry Modification for Safe Mode Persistence

Author
Teoderick Contreras, Michael Haag, Splunk
Source
upstream

The following analytic identifies modifications to the SafeBoot registry keys, specifically within the Minimal and Network paths. This detection leverages registry activity logs from endpoint data sources like Sysmon or EDR tools. Monitoring these keys is crucial as adversaries can use them to persist drivers or services in Safe Mode, with Network allowing network connections. If confirmed malicious, this activity could enable attackers to maintain persistence even in Safe Mode, potentially bypassing certain security measures and facilitating further malicious actions.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
Privilege EscalationT1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE Registry.registry_path IN ("*SYSTEM\\CurrentControlSet\\Control\\SafeBoot\\Minimal\\*", "*SYSTEM\\CurrentControlSet\\Control\\SafeBoot\\Network\\*") 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_pathin
  • "*SYSTEM\\CurrentControlSet\\Control\\SafeBoot\\Minimal\\*"
  • "*SYSTEM\\CurrentControlSet\\Control\\SafeBoot\\Network\\*"