sigmahighHunting

Uncommon FileSystem Load Attempt By Format.com

Detects the execution of format.com with an uncommon filesystem selection that could indicate a defense evasion activity in which "format.com" is used to load malicious DLL files or other programs.

Detection Query

selection:
  Image|endswith: \format.com
  CommandLine|contains: "/fs:"
filter_main_known_fs:
  CommandLine|contains:
    - /fs:exFAT
    - /fs:FAT
    - /fs:NTFS
    - /fs:ReFS
    - /fs:UDF
condition: selection and not 1 of filter_main_*

Author

Florian Roth (Nextron Systems)

Created

2022-01-04

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.stealth

Raw Content

title: Uncommon FileSystem Load Attempt By Format.com
id: 9fb6b26e-7f9e-4517-a48b-8cac4a1b6c60
status: test
description: |
    Detects the execution of format.com with an uncommon filesystem selection that could indicate a defense evasion activity in which "format.com" is used to load malicious DLL files or other programs.
references:
    - https://twitter.com/0gtweet/status/1477925112561209344
    - https://twitter.com/wdormann/status/1478011052130459653?s=20
author: Florian Roth (Nextron Systems)
date: 2022-01-04
modified: 2024-05-13
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\format.com'
        CommandLine|contains: '/fs:'
    filter_main_known_fs:
        CommandLine|contains:
            - '/fs:exFAT'
            - '/fs:FAT'
            - '/fs:NTFS'
            - '/fs:ReFS'
            - '/fs:UDF'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high