WinRAR Execution in Non-Standard Folder — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems), Tigzy. Source status: test; severity: medium. Source dates: 2021-11-17 / 2025-07-16.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: ca5cd0e07f84a53d8706579fbdb6a1baf8a621847d57a8d66bb6a3412c8d2254

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: WinRAR Execution in Non-Standard Folder
id: 4ede543c-e098-43d9-a28f-dd784a13132f
status: test
description: Detects a suspicious WinRAR execution in a folder which is not the default installation folder
references:
    - https://twitter.com/cyb3rops/status/1460978167628406785
author: Florian Roth (Nextron Systems), Tigzy
date: 2021-11-17
modified: 2025-07-16
tags:
    - attack.collection
    - attack.t1560.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith:
              - '\rar.exe'
              - '\winrar.exe'
        - Description:
              - 'Command line RAR'
              - 'WinRAR'
    filter_main_unrar:
        # Note: we filter unrar as it has the same description as the other utilities, and we're only interested in compression
        Image|endswith: '\UnRAR.exe'
    filter_main_path:
        Image|contains:
            - ':\Program Files (x86)\WinRAR\'
            - ':\Program Files\WinRAR\'
    filter_optional_temp:
        # Note: in some occasion installers were seen dropping "rar" in TEMP
        Image|contains: ':\Windows\Temp\'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate use of WinRAR in a folder of a software that bundles WinRAR
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate use of WinRAR in a folder of a software that bundles WinRAR

Source references

• https://twitter.com/cyb3rops/status/1460978167628406785