Detection rules › Splunk

Wermgr Process Create Executable File

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects the wermgr.exe process creating an executable file. It leverages Sysmon EventCode 11 to identify instances where wermgr.exe generates a .exe file. This behavior is unusual because wermgr.exe is typically associated with error reporting, not file creation. Such activity is significant as it may indicate TrickBot malware, which injects code into wermgr.exe to execute malicious actions like downloading additional payloads. If confirmed malicious, this could lead to further malware infections, data exfiltration, or system compromise.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1027 Obfuscated Files or Information

Event coverage

ProviderEvent IDTitle
Sysmon11FileCreate

Stages and Predicates

Stage 1: search

search EventCode=11 TargetFilename="*.exe" process_name="wermgr.exe"

Stage 2: stats

stats BY action, dest, file_name, file_path, process_guid, process_id, user_id, vendor_product

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
EventCodeeq
  • 11 corpus 10 (splunk 10)
TargetFilenameeq
  • "*.exe"
process_nameeq
  • "wermgr.exe"