Detect HTML Help Renamed
The following analytic detects instances where hh.exe (HTML Help) has been renamed and is executing a Compiled HTML Help (CHM) file. This detection leverages data from Endpoint Detection and Response (EDR) agents,…
Description
The following analytic detects instances where hh.exe (HTML Help) has been renamed and is executing a Compiled HTML Help (CHM) file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names. This activity is significant because attackers can use renamed hh.exe to execute malicious scripts embedded in CHM files, potentially leading to code execution. If confirmed malicious, this technique could allow attackers to run arbitrary scripts, escalate privileges, or persist within the environment, posing a significant security risk.
Detection logic
Detection requirements
- Platform
- Windows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- crowdstrike_processrollup2sysmon_eventid_1windows_event_log_security_4688
Known benign triggers
- Although unlikely a renamed instance of hh.exe will be used legitimately, filter as needed.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| attack.mitre.org/techniques/T1218/001/ | 5 |
| github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.001/T1218.001.md | 4 |
| lolbas-project.github.io/lolbas/Binaries/Hh/ | 4 |
From the source
- At source
- Open at source
- Upstream identifier
- 62fed254-513b-460e-953d-79771493a9f3
- Tagged by the source as
- APT37 Rustonotto and FadeStealerLiving Off The LandSuspicious Compiled HTML ActivityEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Oct 6, 2026
- Version
- 2