DD File Overwrite — Sigma Rule

Rule metadata and linked tags

Author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC. Source status: test; severity: low. Source dates: 2021-10-15 / 2022-07-07.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 864cc354ce1607b884e7ab011be852890374b425e9695b2b2d579491feb22a11

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: DD File Overwrite
id: 2953194b-e33c-4859-b9e8-05948c167447
status: test
description: Detects potential overwriting and deletion of a file using DD.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1485/T1485.md#atomic-test-2---macoslinux---overwrite-file-with-dd
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC
date: 2021-10-15
modified: 2022-07-07
tags:
    - attack.impact
    - attack.t1485
logsource:
    product: linux
    category: process_creation
detection:
    selection1:
        Image:
            - '/bin/dd'
            - '/usr/bin/dd'
    selection2:
        CommandLine|contains: 'of='
    selection3:
        CommandLine|contains:
            - 'if=/dev/zero'
            - 'if=/dev/null'
    condition: all of selection*
falsepositives:
    - Any user deleting files that way.
level: low

Original YAML and metadata in JSON

False positives

• Any user deleting files that way.

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1485/T1485.md#atomic-test-2---macoslinux---overwrite-file-with-dd