Detection rules › Sigma

Suspicious GUP Usage

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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

MITRE ATT&CK coverage

Event coverage

Rule body yaml

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

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_*

Stage 1: selection

selection:
    Image|endswith: '\GUP.exe'

Stage 2: not filter_*

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'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imageends_with\AppData\Local\Notepad++\updater\GUP.exe
Imageends_with\AppData\Roaming\Notepad++\updater\GUP.exe
Imagematch\Users\
Imageends_with\Program Files (x86)\Notepad++\updater\GUP.exe
Imageends_with\Program Files\Notepad++\updater\GUP.exe

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \GUP.exe corpus 5 (sigma 5)