File Download Using Notepad++ GUP Utility — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-06-10 / 2023-03-02.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 0f909be6ab9d8a300300f7460003e9bc5139dc02248960befe20771d2fa5d760

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: File Download Using Notepad++ GUP Utility
id: 44143844-0631-49ab-97a0-96387d6b2d7c
status: test
description: Detects execution of the Notepad++ updater (gup) from a process other than Notepad++ to download files.
references:
    - https://twitter.com/nas_bench/status/1535322182863179776
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-10
modified: 2023-03-02
tags:
    - attack.command-and-control
    - attack.t1105
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\GUP.exe'
        - OriginalFileName: 'gup.exe'
    selection_cli:
        CommandLine|contains|all:
            - ' -unzipTo '
            - 'http'
    filter:
        ParentImage|endswith: '\notepad++.exe'
    condition: all of selection* and not filter
falsepositives:
    - Other parent processes other than notepad++ using GUP that are not currently identified
level: high

Original YAML and metadata in JSON

False positives

• Other parent processes other than notepad++ using GUP that are not currently identified

Source references

• https://twitter.com/nas_bench/status/1535322182863179776