Filter Driver Unloaded Via Fltmc.EXE — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-02-13 / 2025-10-07.

{
  "product": "windows",
  "category": "process_creation"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 87b3264ec0cbeeb8234429aad143d49bdefe62f29bef41bce4d87d0f35072e3f

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Filter Driver Unloaded Via Fltmc.EXE
id: 4931188c-178e-4ee7-a348-39e8a7a56821
related:
    - id: 4d7cda18-1b12-4e52-b45c-d28653210df8 # Sysmon specific
      type: derived
status: test
description: Detect filter driver unloading activity via fltmc.exe
references:
    - https://www.darkoperator.com/blog/2018/10/5/operating-offensively-against-sysmon
    - https://www.cybereason.com/blog/threat-analysis-report-lockbit-2.0-all-paths-lead-to-ransom
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-13
modified: 2025-10-07
tags:
    - attack.stealth
    - attack.defense-impairment
    - attack.t1070
    - attack.t1685
    - attack.t1685.001
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\fltMC.exe'
        - OriginalFileName: 'fltMC.exe'
    selection_cli:
        CommandLine|contains: 'unload'
    filter_optional_avira:
        ParentImage|contains:
            - '\AppData\Local\Temp\'
            - ':\Windows\Temp\'
        ParentImage|endswith: '\endpoint-protection-installer-x64.tmp'
        CommandLine|endswith:
            - 'unload rtp_filesystem_filter'
            - 'unload rtp_filter'
    filter_optional_manageengine:
        ParentImage: 'C:\Program Files (x86)\ManageEngine\uems_agent\bin\dcfaservice64.exe'
        CommandLine|endswith: 'unload DFMFilter'
    condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.darkoperator.com/blog/2018/10/5/operating-offensively-against-sysmon
• https://www.cybereason.com/blog/threat-analysis-report-lockbit-2.0-all-paths-lead-to-ransom