Hidden Executable In NTFS Alternate Data Stream

 1title: Hidden Executable In NTFS Alternate Data Stream
 2id: b69888d4-380c-45ce-9cf9-d9ce46e67821
 3status: test
 4description: Detects the creation of an ADS (Alternate Data Stream) that contains an executable by looking at a non-empty Imphash
 5references:
 6    - https://twitter.com/0xrawsec/status/1002478725605273600?s=21
 7author: Florian Roth (Nextron Systems), @0xrawsec
 8date: 2018/06/03
 9modified: 2023/02/10
10tags:
11    - attack.defense_evasion
12    - attack.s0139
13    - attack.t1564.004
14logsource:
15    product: windows
16    category: create_stream_hash
17    definition: 'Requirements: Sysmon or equivalent configured with Imphash logging'
18detection:
19    selection:
20        Hash|contains: 'IMPHASH='
21    filter_main_null:
22        Hash|contains: 'IMPHASH=00000000000000000000000000000000'
23    condition: selection and not 1 of filter_main_*
24falsepositives:
25    - This rule isn't looking for any particular binary characteristics. As legitimate installers and programs were seen embedding hidden binaries in their ADS. Some false positives are expected from browser processes and similar.
26level: medium