Detectionhighexperimental

Uncommon File Created by Notepad++ Updater Gup.EXE

Detects when the Notepad++ updater (gup.exe) creates files in suspicious or uncommon locations. This could indicate potential exploitation of the updater component to deliver unwanted malware or unwarranted files.

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Launch

Swachchhanda Shrawan Poudel (Nextron Systems)Created Tue Feb 033b8f4c92-6a51-4d7e-9c3a-8e2d1f5a7b09windows

Log Source

WindowsFile Event

ProductWindows← raw: windows

CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic

detection:
    selection:
        Image|endswith: '\gup.exe'
    filter_main_legit_paths:
        TargetFilename|startswith:
            - 'C:\Program Files\Notepad++\'
            - 'C:\Program Files (x86)\Notepad++\'
    filter_main_temp_update_installer:
        TargetFilename|startswith: 'C:\Users\'
        TargetFilename|contains|all:
            - '\AppData\Local\Temp\'
            - 'npp.'
            - '.Installer.'
            - '.exe'
    filter_main_temp_generic_zip:
        TargetFilename|startswith: 'C:\Users\'
        TargetFilename|contains|all:
            - '\AppData\Local\Temp\'
            - '.zip'
    filter_main_recycle_bin:
        TargetFilename|startswith: 'C:\$Recycle.Bin\S-1-5-21'
    condition: selection and not 1 of filter_main_*