Suspicious GUP Usage

SIGMA detection rule by Florian Roth (Nextron Systems) · NOASSERTION

Detects execution of the Notepad++ updater in a suspicious directory, which is often used in DLL side-loading attacks

title: Suspicious GUP Usage
id: 0a4f6091-223b-41f6-8743-f322ec84930b
status: test
description: Detects execution of the Notepad++ updater in a suspicious directory, which is often used in DLL side-loading attacks
references:
    - https://www.fireeye.com/blog/threat-research/2018/09/apt10-targeting-japanese-corporations-using-updated-ttps.html
author: Florian Roth (Nextron Systems)
date: 2019-02-06
modified: 2022-08-13
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\GUP.exe'
    filter_programfiles:
        Image|endswith:
            - '\Program Files\Notepad++\updater\GUP.exe'
            - '\Program Files (x86)\Notepad++\updater\GUP.exe'
    filter_user:
        Image|contains: '\Users\'
        Image|endswith:
            - '\AppData\Local\Notepad++\updater\GUP.exe'
            - '\AppData\Roaming\Notepad++\updater\GUP.exe'
    condition: selection and not 1 of filter_*
falsepositives:
    - Execution of tools named GUP.exe and located in folders different than Notepad++\updater
level: high

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

4a414dde-88c6-485d-b178-a8ae9434c7de

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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