Sigma rule: File Encryption/Decryption Via Gpg4win From Suspicious Locations

Rule

Title

File Encryption/Decryption Via Gpg4win From Suspicious Locations

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems), X__Junior (Nextron Systems)

Date

2022-11-30

Modified

2023-08-09

File

rules/windows/process_creation/proc_creation_win_gpg4win_susp_location.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects usage of Gpg4win to encrypt/decrypt files located in potentially suspicious locations.

Log source

product

windows

category

process_creation

Detection

selection_metadata:
    - Image|endswith:
          - '\gpg.exe'
          - '\gpg2.exe'
    - Product: 'GNU Privacy Guard (GnuPG)'
    - Description: 'GnuPG’s OpenPGP tool'
selection_cli:
    CommandLine|contains: '-passphrase'
selection_paths:
    CommandLine|contains:
        - ':\PerfLogs\'
        - ':\Temp\'
        - ':\Users\Public\'
        - ':\Windows\Temp\'
        - '\AppData\Local\Temp\'
        - '\AppData\Roaming\'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution

References

• https://blogs.vmware.com/security/2022/11/batloader-the-evasive-downloader-malware.html
• https://news.sophos.com/en-us/2022/01/19/zloader-installs-remote-access-backdoors-and-delivers-cobalt-strike/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_gpg4win_susp_location.yml