BITS Transfer Job With Uncommon Or Suspicious Remote TLD

title: BITS Transfer Job With Uncommon Or Suspicious Remote TLD
id: 6d44fb93-e7d2-475c-9d3d-54c9c1e33427
status: test
description: Detects a suspicious download using the BITS client from a FQDN that is unusual. Adversaries may abuse BITS jobs to persistently execute or clean up after malicious payloads.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1197/T1197.md
    - https://twitter.com/malmoeb/status/1535142803075960832
author: Florian Roth (Nextron Systems)
date: 2022-06-10
modified: 2025-02-28
tags:
    - attack.persistence
    - attack.execution
    - attack.stealth
    - attack.t1197
logsource:
    product: windows
    service: bits-client
detection:
    selection:
        EventID: 16403
    filter_main_generic:
        RemoteName|contains:
            - '.azureedge.net/'
            - '.com/'
            - '.sfx.ms/'
            - 'download.mozilla.org/' # https://download.mozilla.org/?product=firefox-101.0.1-partial-101.0&os=win64&lang=en-US
            - 'cdn.onenote.net/'
            - 'cdn.office.net/'
            - 'tscdn.m365.static.microsoft/'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - This rule doesn't exclude other known TLDs such as ".org" or ".net". It's recommended to apply additional filters for software and scripts that leverage the BITS service
level: medium