Process Activity via Compiled HTML Fileedit

Compiled HTML files (.chm) are commonly distributed as part of the Microsoft HTML Help system. Adversaries may conceal malicious code in a CHM file and deliver it to a victim for execution. CHM content is loaded by the HTML Help executable program (hh.exe).

Rule type: eql

Rule indices:

  • 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: None


  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Execution

Version: 9

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule queryedit

process where event.type in ("start", "process_started") and : "hh.exe" and : ("mshta.exe", "cmd.exe", "powershell.exe", "pwsh.exe", "cscript.exe", "wscript.exe")