Network Connection via Compiled HTML File
editNetwork Connection 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: 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
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Execution
Version: 11 (version history)
Added (Elastic Stack release): 7.6.0
Last modified (Elastic Stack release): 8.4.0
Rule authors: Elastic
Rule license: Elastic License v2
Rule query
editsequence by process.entity_id [process where process.name : "hh.exe" and event.type == "start"] [network where process.name : "hh.exe" and not cidrmatch(destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29", "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10", "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1", "FE80::/10", "FF00::/8")]
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
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Technique:
- Name: User Execution
- ID: T1204
- Reference URL: https://attack.mitre.org/techniques/T1204/
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Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
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Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
Rule version history
edit- Version 11 (8.4.0 release)
-
- Formatting only
- Version 9 (7.16.0 release)
-
- Formatting only
- Version 8 (7.14.0 release)
-
-
Updated query, changed from:
sequence by process.entity_id [process where process.name : "hh.exe" and event.type == "start"] [network where process.name : "hh.exe" and not cidrmatch(destination.ip, "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16")]
-
- Version 7 (7.12.0 release)
-
- Formatting only
- Version 6 (7.11.0 release)
-
- Formatting only
- Version 5 (7.10.0 release)
-
-
Updated query, changed from:
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)
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- 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)
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- 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
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