sigmalowHunting

Potentially Suspicious Shell Script Creation in Profile Folder

Detects the creation of shell scripts under the "profile.d" path.

Detection Query

selection:
  TargetFilename|contains: /etc/profile.d/
  TargetFilename|endswith:
    - .csh
    - .sh
condition: selection

Author

Joseliyo Sanchez, @Joseliyo_Jstnk

Created

2023-06-02

Data Sources

linuxFile Events

Platforms

linux

References

Tags

attack.persistence

Raw Content

title: Potentially Suspicious Shell Script Creation in Profile Folder
id: 13f08f54-e705-4498-91fd-cce9d9cee9f1
status: test
description: Detects the creation of shell scripts under the "profile.d" path.
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
tags:
    - attack.persistence
logsource:
    product: linux
    category: file_event
detection:
    selection:
        TargetFilename|contains: '/etc/profile.d/'
        TargetFilename|endswith:
            - '.csh'
            - '.sh'
    condition: selection
falsepositives:
    - Legitimate shell scripts in the "profile.d" directory could be common in your environment. Apply additional filter accordingly via "image", by adding specific filenames you "trust" or by correlating it with other events.
    - Regular file creation during system update or software installation by the package manager
level: low # Can be increased to a higher level after some tuning