Windows New Default File Association Value Set
The following analytic detects registry changes to the default file association value. It leverages data from the Endpoint data model, specifically monitoring registry paths under "HKCR\\*\\shell\\open\\command\\*".…
Description
The following analytic detects registry changes to the default file association value. It leverages data from the Endpoint data model, specifically monitoring registry paths under "HKCR\\*\\shell\\open\\command\\*". This activity can be significant because, attackers might alter the default file associations in order to execute arbitrary scripts or payloads when a user opens a file, leading to potential code execution. If confirmed malicious, this technique can enable attackers to persist on the compromised host and execute further malicious commands, posing a severe threat to the environment.
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
- sysmon_eventid_13
Known benign triggers
- Windows and third party software will create and modify these file associations during installation or upgrades. Additional filters needs to be applied to tune environment specific false positives.
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 |
|---|---|
| dmcxblue.gitbook.io/red-team-notes-2-0/red-team-techniques/privilege-escalation/untitled-3/accessibility-features | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- 7d1f031f-f1c9-43be-8b0b-c4e3e8a8928a
- Tagged by the source as
- Data DestructionHermetic WiperPrestige RansomwareWindows Persistence TechniquesWindows Privilege EscalationWindows Registry AbuseEndpointendpointSplunk 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
- Aug 26, 2026
- Version
- 1