BITS Transfer Job Downloading File Potential Suspicious Extension

 1title: BITS Transfer Job Downloading File Potential Suspicious Extension
 2id: b85e5894-9b19-4d86-8c87-a2f3b81f0521
 3status: test
 4description: Detects new BITS transfer job saving local files with potential suspicious extensions
 5references:
 6    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1197/T1197.md
 7author: frack113
 8date: 2022/03/01
 9modified: 2023/03/27
10tags:
11    - attack.defense_evasion
12    - attack.persistence
13    - attack.t1197
14logsource:
15    product: windows
16    service: bits-client
17detection:
18    selection:
19        EventID: 16403
20        LocalName|endswith:
21            # TODO: Extend this list with more interesting file extensions
22            - '.bat'
23            - '.dll'
24            - '.exe' # TODO: Might wanna comment this if it generates tons of FPs
25            - '.hta'
26            - '.ps1'
27            - '.psd1'
28            - '.sh'
29            - '.vbe'
30            - '.vbs'
31    filter_optional_generic:
32        # Typical updates: Chrome, Dropbox etc.
33        LocalName|contains: '\AppData\'
34        RemoteName|contains: '.com'
35    condition: selection and not 1 of filter_optional_*
36falsepositives:
37    - 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
38level: medium