Windows: Detect rar.exe Archive Creation Using Password or Compression Options

title: "Windows: Detect rar.exe Archive Creation Using Password or Compression Options"
id: 1253ce38-bf0c-4232-a840-447f550dc07b
status: test
description: This rule flags process creation where rar.exe is invoked with command-line arguments that include a password flag and other archive configuration flags. Attackers commonly compress and protect files to package sensitive data or evade inspection, making rar command-line usage with these specific options noteworthy. It relies on Windows process creation telemetry and matches on substrings present in the process command line.
references:
  - https://labs.sentinelone.com/the-anatomy-of-an-apt-attack-and-cobaltstrike-beacons-encoded-configuration/
  - https://ss64.com/bash/rar.html
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1560.001/T1560.001.md
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_rar_compression_with_password.yml
author: "@ROxPinTeddy, Huntrule Team"
date: 2020-05-12
modified: 2022-03-16
tags:
  - attack.collection
  - attack.t1560.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_password:
    CommandLine|contains: " -hp"
  selection_other:
    CommandLine|contains:
      - " -m"
      - " a "
  condition: selection_password and selection_other
falsepositives:
  - Legitimate use of Winrar command line version
  - Other command line tools, that use these flags
level: high
license: DRL-1.1
related:
  - id: faa48cae-6b25-4f00-a094-08947fef582f
    type: derived