Sigma rule: Potential PHP Reverse Shell

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-b7bb911dddc4, updated 2023-04-07T00:00:00.000Z.

Rule

Title
Potential PHP Reverse Shell
Status
test
Level
high
Author
@d4ns4n_
Date
2023-04-07
File
rules/linux/process_creation/proc_creation_lnx_php_reverse_shell.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product
linux
category
process_creation

Detection

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

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.execution

References

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

Sources and licences

  • SigmaHQ

    "Potential PHP Reverse Shell" by @d4ns4n_ (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/process_creation/proc_creation_lnx_php_reverse_shell.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Potential PHP Reverse Shell",
entity page, dataset version ref-b7bb911dddc4, updated 2023-04-07T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/c6714a24-d7d5-4283-a36b-3ffd091d5f7e (accessed 2026-11-03).
Underlying source: SigmaHQ rule c6714a24-d7d5-4283-a36b-3ffd091d5f7e, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.