file_event_win_office_onenote_files_in_susp_locations.yml

title: OneNote Attachment File Dropped In Suspicious Location
id: 7fd164ba-126a-4d9c-9392-0d4f7c243df0
status: experimental
description: Detects creation of files with the ".one"/".onepkg" extension in suspicious or uncommon locations. This could be a sign of attackers abusing OneNote attachments
references:
    - https://www.bleepingcomputer.com/news/security/hackers-now-use-microsoft-onenote-attachments-to-spread-malware/
    - https://blog.osarmor.com/319/onenote-attachment-delivers-asyncrat-malware/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023/01/22
modified: 2023/09/19
tags:
    - attack.defense_evasion
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|contains:
            # Note: add more common locations for drops such as download folders and the like. Or baseline legitimate locations and alert on everything else
            - '\AppData\Local\Temp\'
            - '\Users\Public\'
            - '\Windows\Temp\'
            - ':\Temp\'
        TargetFilename|endswith:
            - '.one'
            - '.onepkg'
    filter_main_onenote:
        Image|contains: ':\Program Files\Microsoft Office\'
        Image|endswith: '\ONENOTE.EXE'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate usage of ".one" or ".onepkg" files from those locations
level: medium