Suspicious Registry Change to Hidden File Extension (via registry_set)

title: Suspicious Registry Change to Hidden File Extension (via registry_set)
id: 6f7c490d-7e59-5e37-b741-860be3a40758
status: stable
description: This rule detects hides the file extension through modification of the registry
references:
    - https://attack.mitre.org/techniques/T1137/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1112/T1112.md#atomic-test-1---modify-registry-of-current-user-profile---cmd
    - https://unit42.paloaltonetworks.com/ransomware-families/
    - https://www.microsoft.com/en-us/wdsi/threats/malware-encyclopedia-description?name=TrojanSpy%3aMSIL%2fHakey.A
author: Huntrule Team
date: 2026-04-19
tags:
    - attack.persistence
    - attack.t1137
logsource:
    category: registry_set
    product: windows
detection:
    selection_HideFileExt:
        TargetObject|endswith: '\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\HideFileExt'
        Details: 'DWORD (0x00000001)'
    selection_Hidden:
        TargetObject|endswith: '\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Hidden'
        Details: 'DWORD (0x00000002)'
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: medium