sigmahighHunting

Potential PHP Reverse Shell

Detects usage of the PHP CLI with the "-r" flag which allows it to run inline PHP code. The rule looks for calls to the "fsockopen" function which allows the creation of sockets. Attackers often leverage this in combination with functions such as "exec" or "fopen" to initiate a reverse shell connection.

Detection Query

selection:
  Image|contains: /php
  CommandLine|contains|all:
    - " -r "
    - fsockopen
  CommandLine|contains:
    - ash
    - bash
    - bsh
    - csh
    - ksh
    - pdksh
    - sh
    - tcsh
    - zsh
condition: selection

Author

@d4ns4n_

Created

2023-04-07

Data Sources

linuxProcess Creation Events

Platforms

linux

References

Tags

attack.execution

Raw Content

title: Potential PHP Reverse Shell
id: c6714a24-d7d5-4283-a36b-3ffd091d5f7e
status: test
description: |
    Detects usage of the PHP CLI with the "-r" flag which allows it to run inline PHP code. The rule looks for calls to the "fsockopen" function which allows the creation of sockets.
    Attackers often leverage this in combination with functions such as "exec" or "fopen" to initiate a reverse shell connection.
references:
    - https://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet
    - https://www.revshells.com/
author: '@d4ns4n_'
date: 2023-04-07
tags:
    - attack.execution
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|contains: '/php'
        CommandLine|contains|all:
            - ' -r '
            - 'fsockopen'
        CommandLine|contains:
            - 'ash'
            - 'bash'
            - 'bsh'
            - 'csh'
            - 'ksh'
            - 'pdksh'
            - 'sh'
            - 'tcsh'
            - 'zsh'
    condition: selection
falsepositives:
    - Unknown
level: high