Detection rules › Sigma
Potential DLL Sideloading Via JsSchHlp
Detects potential DLL sideloading using JUSTSYSTEMS Japanese word processor
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
title: Potential DLL Sideloading Via JsSchHlp
id: 68654bf0-4412-43d5-bfe8-5eaa393cd939
status: test
description: Detects potential DLL sideloading using JUSTSYSTEMS Japanese word processor
references:
- 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: frack113
date: 2022-12-14
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
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
ImageLoaded|endswith: '\JSESPR.dll'
Stage 2: not filter
filter:
ImageLoaded|startswith: 'C:\Program Files\Common Files\Justsystem\JsSchHlp\'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
ImageLoaded | starts_with | C:\Program Files\Common Files\Justsystem\JsSchHlp\ | excludes:ImageLoaded field:"ImageLoaded" value:"C:\Program Files\Common Files\Justsystem\JsSchHlp\" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
ImageLoaded | ends_with |
| field:"ImageLoaded" kind:ends_with value:"\JSESPR.dll" |