Linux dd Command Overwrite or Deletion via of= and input redirection

Flags Linux dd executions that use of= with /dev/zero or /dev/null, consistent with file overwrite or deletion attempts.

FreeReviewedSigma · Low · v3
Product
linux
Category
process_creation
Author
Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC (SigmaHQ), DRL 1.1
Published
2021-10-15
Updated
2026-07-31
title: Linux dd Command Overwrite or Deletion via of= and input redirection
id: dfafd658-bd32-45ed-9a93-3c4199874a8c
status: test
description: This rule flags Linux process creations where dd is invoked with output redirection (of=) and an input source that can indicate wiping or nulling (/dev/zero or /dev/null). Attackers may use dd to overwrite or delete data by writing raw bytes directly to files or devices. The detection relies on process creation telemetry including the executed image path and the command-line arguments used by dd.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1485/T1485.md#atomic-test-2---macoslinux---overwrite-file-with-dd
  - https://github.com/SigmaHQ/sigma/blob/master/rules/linux/process_creation/proc_creation_lnx_dd_file_overwrite.yml
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC, Huntrule Team
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
license: DRL-1.1
related:
  - id: 2953194b-e33c-4859-b9e8-05948c167447
    type: derived