title: 'Binary Padding'
id: 95361ce5-c891-4b0a-87ca-e24607884a96
status: test
description: 'Adversaries may use binary padding to add junk data and change the on-disk representation of malware. This rule detect using dd and truncate to add a junk data to file.'
author: 'Igor Fits, Mikhail Larin, oscd.community'
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1027.001/T1027.001.md
date: 2020/10/19
modified: 2021/11/27
logsource:
  product: macos
  category: process_creation
detection:
  selection1:
    Image|endswith:
      - '/truncate'
    CommandLine|contains:
      - '-s'
  selection2:
    Image|endswith:
      - '/dd'
    CommandLine|contains:
      - 'if='
  filter:
    CommandLine|contains: 'of='
  condition: selection1 or (selection2 and not filter)
falsepositives:
  - 'Legitimate script work'
level: high
tags:
  - attack.defense_evasion
  - attack.t1027.001