Unusual Child Processes of RunDLL32

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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:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Defense Evasion
  • Data Source: Elastic Defend

Version: 105

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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sequence with maxspan=1h
  [process where host.os.type == "windows" and 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 host.os.type == "windows" and event.type == "start" and process.parent.name : "rundll32.exe"
  ] by process.parent.entity_id

Framework: MITRE ATT&CKTM