Possible DLL Sideloading Through JsSchHlp (via image_load)

title: Possible DLL Sideloading Through JsSchHlp (via image_load)
id: 812cc74f-851d-59d2-be3f-d1cc70897419
status: stable
description: This rule detects potential DLL sideloading using JUSTSYSTEMS Japanese word processor
references:
    - https://attack.mitre.org/techniques/T1574/001/
    - https://www.welivesecurity.com/2022/12/14/unmasking-mirrorface-operation-liberalface-targeting-japanese-political-entities/
    - http://www.windowexe.com/bbs/board.php?q=jsschhlp-exe-c-program-files-common-files-justsystem-jsschhlp-jsschhlp
author: Huntrule Team
date: 2026-01-09
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\JSESPR.dll'
    filter:
        ImageLoaded|startswith: 'C:\Program Files\Common Files\Justsystem\JsSchHlp\'
    condition: selection and not filter
falsepositives:
    - Unknown
level: medium