Suspicious Image Load (taskschd.dll) from MS Office

Identifies a suspicious image load (taskschd.dll) from Microsoft Office processes. This behavior may indicate adversarial activity where a scheduled task is configured via Windows Component Object Model (COM). This technique can be used to configure persistence and evade monitoring by avoiding the usage of the traditional Windows binary (schtasks.exe) used to manage scheduled tasks.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*

Severity: low

Risk score: 21

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Elastic
Host
Windows
Threat Detection
Persistence

Version: 101

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

edit

Rule query

edit

any where
 (event.category == "library" or (event.category == "process" and event.action : "Image loaded*")) and
  process.name : ("WINWORD.EXE", "EXCEL.EXE", "POWERPNT.EXE", "MSPUB.EXE", "MSACCESS.EXE") and
  (dll.name : "taskschd.dll" or file.name : "taskschd.dll")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Scheduled Task/Job
- ID: T1053
- Reference URL: https://attack.mitre.org/techniques/T1053/

« Component Object Model Hijacking Suspicious Execution via Scheduled Task »