Detection rules › Sigma
Potentially Suspicious Execution From Tmp Folder
Detects a potentially suspicious execution of a process located in the '/tmp/' folder
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1036 Masquerading |
Event coverage
| Provider | Event |
|---|---|
| Sysmon-for-Linux | Event ID 1 |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_optional_*Stage 1: selection
selection:
Image|startswith: '/tmp/'
Stage 2: not filter_optional_nextcloud
filter_optional_nextcloud:
Image|endswith: '/usr/bin/nextcloud'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Image | ends_with | /usr/bin/nextcloud |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | starts_with |
|