Execution of Possible Fake Instance Of Hxtsr.EXE (via process_creation)

title: Execution of Possible Fake Instance Of Hxtsr.EXE (via process_creation)
id: e946d89e-0abd-5c05-bcac-f2afb39658ce
status: stable
description: This rule detects HxTsr.exe is a Microsoft compressed executable file called Microsoft Outlook Communications. HxTsr.exe is part of Outlook apps, because it resides in a hidden "WindowsApps" subfolder of "C:\Program Files". Any instances of hxtsr.exe not in this folder may be malware camouflaging itself as HxTsr.exe
references:
    - https://attack.mitre.org/techniques/T1036/
    - Internal Research
author: Huntrule Team
date: 2026-06-05
tags:
    - attack.stealth
    - attack.t1036
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        Image|endswith: '\hxtsr.exe'
    filter_main_hxtsr:
        Image|contains: ':\program files\windowsapps\microsoft.windowscommunicationsapps_'
        Image|endswith: '\hxtsr.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium