Windows.EventLogs.SysmonProcessEnriched.yaml

name: Windows.EventLogs.SysmonProcessEnriched.yaml
author: Zane Gittins
description: |
   Collects sysmon process creation events and enriches with authenticode signature, tlsh hash, and call chain. Requires Sysmon and the process tracker.
reference:
 - https://signalsleuth.io/2025/08/31/sysmon_enrichment.html

type: CLIENT_EVENT

parameters:
  - name: CachePeriod
    default: 3600
    description: Cache the authenticode signature and tlsh hash of a image for this duration of seconds.
    type: int64
  - name: TLSHImageRegex
    default: "AppData|Downloads|Desktop|Public|Temp"
    description: If an image matches this regex, calculate the TLSH hash.
    type: regex

sources:
  - precondition:
      SELECT OS From info() where OS = 'windows'

    query: |
      LET get_auth_cache(Image) = authenticode(filename=Image)
      
      LET get_tlsh_cache(Image) = tlsh_hash(path=Image)
      
      SELECT *, cache(period=CachePeriod,
                      func=get_auth_cache(Image=EventData.Image),
                      key=str(str=EventData.Hashes),
                      name="auth") AS Authenticode,
             if(condition=(EventData.Image =~ TLSHImageRegex),
                then=cache(period=CachePeriod,
                           func=get_tlsh_cache(Image=EventData.Image),
                           key=str(str=EventData.Hashes),
                           name="tlsh")) AS TLSH,
             join(array=process_tracker_callchain(id=EventData.ProcessId).Data.Name,
                  sep="->") AS CallChain
      FROM delay(
        query={
          SELECT *
          FROM watch_evtx(
            filename="C:\\Windows\\system32\\winevt\\Logs\\Microsoft-Windows-Sysmon%4Operational.evtx")
          WHERE System.EventID.Value = 1
        },
        delay=1)
resources:
  max_rows: 1000