Windows Registry Event Triggered by RedMimicry Winnti Playbook (HTMLHelp\data)

Alerts on Windows registry events targeting HKLM\SOFTWARE\Microsoft\HTMLHelp\data associated with the RedMimicry Winnti playbook.

FreeReviewedSigma · High · v1
Product
windows
Category
registry_event
Author
Alexander Rausch (SigmaHQ), DRL 1.1
Published
2020-06-24
Updated
2026-07-30
title: Windows Registry Event Triggered by RedMimicry Winnti Playbook (HTMLHelp\data)
id: 55c1b903-bee4-4ea2-bf6a-1072cf015f41
status: test
description: This rule flags Windows registry events where the target object path contains HKLM\SOFTWARE\Microsoft\HTMLHelp\data, indicating manipulation under the HTML Help data location. Attackers may use such persistence or defense-impairment related registry changes to influence system behavior. The detection relies on Windows registry event telemetry capturing the TargetObject value associated with the action.
references:
  - https://redmimicry.com
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_event/registry_event_redmimicry_winnti_reg.yml
author: Alexander Rausch, Huntrule Team
date: 2020-06-24
modified: 2021-11-27
tags:
  - attack.persistence
  - attack.defense-impairment
  - attack.t1112
logsource:
  product: windows
  category: registry_event
detection:
  selection:
    TargetObject|contains: HKLM\SOFTWARE\Microsoft\HTMLHelp\data
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 5b175490-b652-4b02-b1de-5b5b4083c5f8
    type: derived