Detection rules › Splunk

Registry Keys for Creating SHIM Databases

Author
Patrick Bareiss, Teoderick Contreras, Splunk, Steven Dick, Bhavin Patel
Source
upstream

The following analytic detects registry activity related to the creation of application compatibility shims. It leverages data from the Endpoint.Registry data model, specifically monitoring registry paths associated with AppCompatFlags. This activity is significant because attackers can use shims to bypass security controls, achieve persistence, or escalate privileges. If confirmed malicious, this could allow an attacker to maintain long-term access, execute arbitrary code, or manipulate application behavior, posing a severe risk to the integrity and security of the affected systems.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1546.011 Event Triggered Execution: Application Shimming
Privilege EscalationT1546.011 Event Triggered Execution: Application Shimming

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: tstats

tstats WHERE (Registry.registry_path="*CurrentVersion\\\\AppCompatFlags\\\\Custom*" OR Registry.registry_path="*CurrentVersion\\\\AppCompatFlags\\\\InstalledSDB*") 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: where

where isnotnull(registry_value_data)

Stage 4: search

search

Stage 5: search

search

Stage 6: 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
  • *CurrentVersion\\AppCompatFlags\\Custom*
  • *CurrentVersion\\AppCompatFlags\\InstalledSDB*