Potential Ransomware or Unauthorized MBR Tampering Via Bcdedit.EXE — Sigma Rule

Rule metadata and linked tags

Author: @neu5ron. Source status: test; severity: medium. Source dates: 2019-02-07 / 2023-02-15.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d239927c564f654165ce4f1fe5ef290fbe9b8802e61644d0c9aa354bc79cb946

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: Potential Ransomware or Unauthorized MBR Tampering Via Bcdedit.EXE
id: c9fbe8e9-119d-40a6-9b59-dd58a5d84429
status: test
description: Detects potential malicious and unauthorized usage of bcdedit.exe
references:
    - https://learn.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--set
    - https://twitter.com/malwrhunterteam/status/1372536434125512712/photo/2
author: '@neu5ron'
date: 2019-02-07
modified: 2023-02-15
tags:
    - attack.stealth
    - attack.t1070
    - attack.persistence
    - attack.t1542.003
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\bcdedit.exe'
        - OriginalFileName: 'bcdedit.exe'
    selection_cli:
        CommandLine|contains:
            - 'delete'
            - 'deletevalue'
            - 'import'
            - 'safeboot'
            - 'network'
    condition: all of selection_*
level: medium

Original YAML and metadata in JSON

False positives

No reviewed association in this snapshot.

Source references

• https://learn.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--set
• https://twitter.com/malwrhunterteam/status/1372536434125512712/photo/2