BITS Transfer Job With Uncommon Or Suspicious Remote TLD

calendar Apr 28, 2026 · attack.persistence attack.execution attack.stealth attack.t1197  ·
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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.

Sigma rule (View on GitHub)

 1title: BITS Transfer Job With Uncommon Or Suspicious Remote TLD
 2id: 6d44fb93-e7d2-475c-9d3d-54c9c1e33427
 3status: test
 4description: 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.
 5references:
 6    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1197/T1197.md
 7    - https://twitter.com/malmoeb/status/1535142803075960832
 8author: Florian Roth (Nextron Systems)
 9date: 2022-06-10
10modified: 2025-02-28
11tags:
12    - attack.persistence
13    - attack.execution
14    - attack.stealth
15    - attack.t1197
16logsource:
17    product: windows
18    service: bits-client
19detection:
20    selection:
21        EventID: 16403
22    filter_main_generic:
23        RemoteName|contains:
24            - '.azureedge.net/'
25            - '.com/'
26            - '.sfx.ms/'
27            - 'download.mozilla.org/' # https://download.mozilla.org/?product=firefox-101.0.1-partial-101.0&os=win64&lang=en-US
28            - 'cdn.onenote.net/'
29            - 'cdn.office.net/'
30            - 'tscdn.m365.static.microsoft/'
31    condition: selection and not 1 of filter_main_*
32falsepositives:
33    - 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
34level: medium

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