ImageLoad via Windows Update Auto Update Client
editImageLoad via Windows Update Auto Update Clientedit
Identifies abuse of the Windows Update Auto Update Client (wuauclt.exe) to load an arbitrary DLL. This behavior is used as a defense evasion technique to blend in malicious activity with legitimate Windows software.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
- winlogbeat-*
- logs-windows.*
Severity: medium
Risk score: 47
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
- Defense Evasion
Version: 6
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
process where event.type in ("start", "process_started") and
(process.pe.original_file_name == "wuauclt.exe" or process.name : "wuauclt.exe") and
/* necessary windows update client args to load a dll */
process.args : "/RunHandlerComServer" and process.args : "/UpdateDeploymentProvider" and
/* common paths writeable by a standard user where the target DLL can be placed */
process.args : ("C:\\Users\\*.dll", "C:\\ProgramData\\*.dll", "C:\\Windows\\Temp\\*.dll", "C:\\Windows\\Tasks\\*.dll")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Signed Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/