SecurityNotFound - 404 Page Not Found Webshell

If the attacker can enter the system, they will be put a backdoor called webshell to backconnect into web server of course and also to interact with server. Webshell is usually a PHP script or ASP script that we can upload it to victim website, after uploading the webshell is can be access from URL and then you can do everything on website.

Overview

SecurityNotFound is a PHP webshell that display 404 not found page, but if you know the secret, that 404 page is just a fake display, this technique is acctually just to cover it up and also make this shell is secure because there is just you who can open the shell.

You can follow instructions bellow to understand how to 404 Page Not Found Webshell is working.

Clone me!

Clone or download the project:

git clone https://github.com/CosasDePuma/SecurityNotFound.git SecurityNotFound
cd SecurityNotFound

Installation

The src/404.php file should be located on the target server.

That server must have the ability to execute .php files.

Here is an example of some of the most common routes on which servers are located:

# 🏁 Windows (Xampp)
C:\Xampp\htdocs\
 
# 🐧 Linux
/var/www/html/

Obviously, you and I know that you have legitimate access to that server.

Access Granted!

Now, you can access it through the browser:

https://www.target.com/404.php

404 Page Not Found Webshell - how to access 404 shell

You can replace the server 404 error template to access from any invalid URL.

How to access 404 Not Found Webshell

To access the control panel, press TAB key or search the password field using your browser’s tools.

404 Page Not Found Webshell - how to access 404 shell xploitlab

The default password is: cosasdepuma.

You can leave the $passphrase variable in the script as an empty string to directly access the control panel. If it is your intention, you have lost my respect.

To set a custom value, insert your password into the $passphrase variable after applying the MD5 algorithm three consecutive times.

Control Panel

You can also log out using the exit parameter in a GET request.

Buttons

Name	Function
PHPINFO	Shows `phpinfo();` page.
EXPLOIT-DB	Searches for kernel-compatible exploits in `exploit-db.com`.
GEOLOCATE	It shows approximately in `Google Maps` the place where the server is physically located.
CRYPTOMINER	Add a JS Cryptominer (CoinImp) to the `.php` and `.html` files in the same folder with the `</body>` tag.
SELF-REMOVE	The shell deletes itself from the server.