SigmaHQ/rules/windows/process_creation/win_data_compressed_with_rar.yml

title: Data Compressed - rar.exe
id: 6f3e2987-db24-4c78-a860-b4f4095a7095
status: experimental
description: An adversary may compress data (e.g., sensitive documents) that is collected prior to exfiltration in order to make it portable and minimize the amount of data sent over the network.
author: Timur Zinniatullin, E.M. Anhaus, oscd.community
date: 2019/10/21
modified: 2020/08/29
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1560.001/T1560.001.md
    - https://eqllib.readthedocs.io/en/latest/analytics/1ec33c93-3d0b-4a28-8014-dbdaae5c60ae.html
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\rar.exe'
        CommandLine|contains: ' a '
    condition: selection
fields:
    - Image
    - CommandLine
    - User
    - LogonGuid
    - Hashes
    - ParentProcessGuid
    - ParentCommandLine
falsepositives:
    - Highly likely if rar is a default archiver in the monitored environment.
level: low
tags:
    - attack.exfiltration  # an old one
    - attack.t1002  # an old one
    - attack.collection
    - attack.t1560.001