The SIEM app is now a part of the Elastic Security solution. Click here to view SIEM documentation for previous releases.
« Network Connection via Certutil Network Connection via MsXsl »
Elastic Docs ›Elastic Security Solution [7.9] ›Detections and Alerts (beta) ›Prebuilt rule reference

Network Connection via Compiled HTML File

edit

Network Connection via Compiled HTML File

edit

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: query

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*

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

Tags:

  • Elastic
  • Windows

Version: 4 (version history)

Added (Elastic Stack release): 7.6.0

Last modified (Elastic Stack release): 7.9.1

Rule authors: Elastic

Rule license: Elastic License

Rule query

edit
event.category:network and event.type:connection and
process.name:hh.exe and not destination.ip:(10.0.0.0/8 or
172.16.0.0/12 or 192.168.0.0/16)

Threat mapping

edit

Framework: MITRE ATT&CKTM

Rule version history

edit
Version 4 (7.9.1 release)
  • Formatting only
Version 3 (7.9.0 release)

  • Updated query, changed from:

    process.name:hh.exe and event.action:"Network connection detected
(rule: NetworkConnect)" and not destination.ip:(10.0.0.0/8 or
172.16.0.0/12 or 192.168.0.0/16)
Version 2 (7.7.0 release)

  • Updated query, changed from:

    process.name:hh.exe and event.action:"Network connection detected
(rule: NetworkConnect)" and not destination.ip:10.0.0.0/8 and not
destination.ip:172.16.0.0/12 and not destination.ip:192.168.0.0/16
« Network Connection via Certutil Network Connection via MsXsl »