Unusual Child Processes of RunDLL32

Identifies child processes of unusual instances of RunDLL32 where the command line parameters were suspicious. Misuse of RunDLL32 could indicate malicious activity.

Rule type: eql

Rule indices:

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

Severity: high

Risk score: 73

Runs every: 30m

Searches indices from: now-60m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

Elastic
Host
Windows
Threat Detection
Defense Evasion

Version: 101

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

sequence with maxspan=1h
  [process where event.type == "start" and
     (process.name : "rundll32.exe" or process.pe.original_file_name == "RUNDLL32.EXE") and
      process.args_count == 1
  ] by process.entity_id
  [process where event.type == "start" and process.parent.name : "rundll32.exe"
  ] by process.parent.entity_id

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
Sub-technique:
- Name: Rundll32
- ID: T1218.011
- Reference URL: https://attack.mitre.org/techniques/T1218/011/

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