Winrar Compressing Dump Files — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-01-04 / 2023-09-12.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8a89765d94c9de6fb5cc54e3caf0c9550ee896dffeee93153e3ea6fef9b79878

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 Compressing Dump Files
id: 1ac14d38-3dfc-4635-92c7-e3fd1c5f5bfc
related:
    - id: ec570e53-4c76-45a9-804d-dc3f355ff7a7
      type: similar
status: test
description: Detects execution of WinRAR in order to compress a file with a ".dmp"/".dump" extension, which could be a step in a process of dump file exfiltration.
references:
    - https://www.crowdstrike.com/blog/overwatch-exposes-aquatic-panda-in-possession-of-log-4-shell-exploit-tools/
author: Florian Roth (Nextron Systems)
date: 2022-01-04
modified: 2023-09-12
tags:
    - attack.collection
    - attack.t1560.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\rar.exe'
              - '\winrar.exe'
        - Description: 'Command line RAR'
    selection_extension:
        CommandLine|contains:
            - '.dmp'
            - '.dump'
            - '.hdmp'
    condition: all of selection_*
falsepositives:
    - Legitimate use of WinRAR with a command line in which ".dmp" or ".dump" appears accidentally
    - Legitimate use of WinRAR to compress WER ".dmp" files for troubleshooting
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate use of WinRAR with a command line in which ".dmp" or ".dump" appears accidentally
• Legitimate use of WinRAR to compress WER ".dmp" files for troubleshooting

Source references

• https://www.crowdstrike.com/blog/overwatch-exposes-aquatic-panda-in-possession-of-log-4-shell-exploit-tools/