This documentation contains work-in-progress information for future Elastic Stack and Cloud releases. Use the version selector to view supported release docs. It also contains some Elastic Cloud serverless information. Check out our serverless docs for more details.
Process Activity via Compiled HTML File
editProcess Activity via Compiled HTML File
editCompiled 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-endpoint.events.*
- 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
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Execution
Version: 11
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Config If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
Rule query
editprocess where event.type in ("start", "process_started") and process.parent.name : "hh.exe" and process.name : ("mshta.exe", "cmd.exe", "powershell.exe", "pwsh.exe", "powershell_ise.exe", "cscript.exe", "wscript.exe")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: User Execution
- ID: T1204
- Reference URL: https://attack.mitre.org/techniques/T1204/
-
Sub-technique:
- Name: Malicious File
- ID: T1204.002
- Reference URL: https://attack.mitre.org/techniques/T1204/002/
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Signed Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
-
Sub-technique:
- Name: Compiled HTML File
- ID: T1218.001
- Reference URL: https://attack.mitre.org/techniques/T1218/001/