Suspicious File Encryption Via Gpg4win (via process_creation)

This rule detects use of Gpg4win to encrypt files

SigmamediumWindowsv1
sigma
title: Suspicious File Encryption Via Gpg4win (via process_creation)
id: e82a9925-b632-5940-be42-0a9d7dbb40fc
status: stable
description: This rule detects use of Gpg4win to encrypt files
references:
    - https://blogs.vmware.com/security/2022/11/batloader-the-evasive-downloader-malware.html
    - https://www.gpg4win.de/documentation.html
    - https://news.sophos.com/en-us/2022/01/19/zloader-installs-remote-access-backdoors-and-delivers-cobalt-strike/
author: Huntrule Team
date: 2026-07-15
tags:
    - attack.execution
    - attack.impact
    - attack.collection
    - attack.t1486
    - attack.t1560.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_metadata:
        - Image|endswith:
              - '\gpg.exe'
              - '\gpg2.exe'
        - Description: 'GnuPG’s OpenPGP tool'
    selection_cli:
        CommandLine|contains|all:
            - ' -c '
            - 'passphrase'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.