Suspicious Image Load (taskschd.dll) from MS Officeedit
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: 5 minutes
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: 4 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 8.2.0
Rule authors: Elastic
Rule license: Elastic License v2
Investigation guideedit
## Config If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
Rule queryedit
library where process.name : ("WINWORD.EXE", "EXCEL.EXE", "POWERPNT.EXE", "MSPUB.EXE", "MSACCESS.EXE") and event.action : "load" and event.category : "library" and dll.name : "taskschd.dll"
Threat mappingedit
Framework: MITRE ATT&CKTM
-
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/
Rule version historyedit
- Version 4 (8.2.0 release)
-
- Formatting only
- Version 3 (7.12.0 release)
-
-
Updated query, changed from:
library where process.name in ("WINWORD.EXE", "EXCEL.EXE", "POWERPNT.EXE", "MSPUB.EXE", "MSACCESS.EXE") and event.action == "load" and event.category == "library" and file.name == "taskschd.dll"
-
- Version 2 (7.11.2 release)
-
- Formatting only