BITS Transfer Job Downloading File Potential Suspicious Extension

title: BITS Transfer Job Downloading File Potential Suspicious Extension
id: b85e5894-9b19-4d86-8c87-a2f3b81f0521
status: test
description: Detects new BITS transfer job saving local files with potential suspicious extensions
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1197/T1197.md
author: frack113
date: 2022-03-01
modified: 2023-03-27
tags:
    - attack.defense-evasion
    - attack.persistence
    - attack.t1197
logsource:
    product: windows
    service: bits-client
detection:
    selection:
        EventID: 16403
        LocalName|endswith:
            # TODO: Extend this list with more interesting file extensions
            - '.bat'
            - '.dll'
            - '.exe' # TODO: Might wanna comment this if it generates tons of FPs
            - '.hta'
            - '.ps1'
            - '.psd1'
            - '.sh'
            - '.vbe'
            - '.vbs'
    filter_optional_generic:
        # Typical updates: Chrome, Dropbox etc.
        LocalName|contains: '\AppData\'
        RemoteName|contains: '.com'
    condition: selection and not 1 of filter_optional_*
falsepositives:
    - While the file extensions in question can be suspicious at times. It's best to add filters according to your environment to avoid large amount false positives
level: medium