Detection rules › Splunk

Shim Database File Creation

Author
David Dorsey, Splunk
Source
upstream

The following analytic detects the creation of shim database files (.sdb) in default directories using the sdbinst.exe application. It leverages filesystem activity data from the Endpoint.Filesystem data model to identify file writes to the Windows\AppPatch\Custom directory. This activity is significant because shims can intercept and alter API calls, potentially allowing attackers to bypass security controls or execute malicious code. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment.

MITRE ATT&CK coverage

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

Event coverage

ProviderEvent IDTitle
Sysmon11FileCreate

Stages and Predicates

Stage 1: tstats

tstats WHERE Filesystem.file_path="*Windows\\\\AppPatch\\\\Custom*" BY Filesystem.action, Filesystem.dest, Filesystem.file_access_time, Filesystem.file_create_time, Filesystem.file_hash, Filesystem.file_modify_time, Filesystem.file_name, Filesystem.file_path, Filesystem.file_acl, Filesystem.file_size, Filesystem.process_guid, Filesystem.process_id, Filesystem.user, Filesystem.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
Filesystem.file_patheq
  • *Windows\\AppPatch\\Custom*