Potentially Suspicious Execution From Tmp Folder — Sigma Rule

Rule metadata and linked tags

Author: Joseliyo Sanchez, @Joseliyo_Jstnk. Source status: test; severity: medium. Source dates: 2023-06-02 / 2025-08-05.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 70079d6229ed039d1dd45b6c730fb8f9d3be4bfe51211e7d786d59cbcea16e9d

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: Potentially Suspicious Execution From Tmp Folder
id: 312b42b1-bded-4441-8b58-163a3af58775
status: test
description: Detects a potentially suspicious execution of a process located in the '/tmp/' folder
references:
    - https://blogs.jpcert.or.jp/en/2023/05/gobrat.html
    - https://jstnk9.github.io/jstnk9/research/GobRAT-Malware/
    - https://www.virustotal.com/gui/file/60bcd645450e4c846238cf0e7226dc40c84c96eba99f6b2cffcd0ab4a391c8b3/detection
    - https://www.virustotal.com/gui/file/3e44c807a25a56f4068b5b8186eee5002eed6f26d665a8b791c472ad154585d1/detection
author: Joseliyo Sanchez, @Joseliyo_Jstnk
date: 2023-06-02
modified: 2025-08-05
tags:
    - attack.stealth
    - attack.t1036
logsource:
    product: linux
    category: process_creation
detection:
    selection:
        Image|startswith: '/tmp/'
    filter_optional_nextcloud:
        Image|endswith: '/usr/bin/nextcloud'
    condition: selection and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://blogs.jpcert.or.jp/en/2023/05/gobrat.html
• https://jstnk9.github.io/jstnk9/research/GobRAT-Malware/
• https://www.virustotal.com/gui/file/60bcd645450e4c846238cf0e7226dc40c84c96eba99f6b2cffcd0ab4a391c8b3/detection
• https://www.virustotal.com/gui/file/3e44c807a25a56f4068b5b8186eee5002eed6f26d665a8b791c472ad154585d1/detection