Penetration Testing Tools: 6 Free Tools You Should Know

What Are Penetration Testing Tools?

Penetration testing (pentesting) is a cybersecurity practice that allows organizations to identify software vulnerabilities and weaknesses in their network’s security. It involves attempting to hack or compromise a system to determine how malicious actors might exploit vulnerabilities and evade existing security mechanisms.

Various types of tools can be used to test and highlight issues in applications, operating systems, and networks. Organizations choose their pentesting tools based on the types of vulnerabilities they prioritize, their existing technologies, and budgetary constraints. Both open source and paid tools can help improve a business’s security posture.

Types of Penetration Testing Tools

There are various tools organizations can use for penetration testing, each providing different insights into the organization’s current security posture. Here are common types of penetration testing tools to consider:

Port scanners

A port scanner can identify open ports on a system to help find all operating systems and applications running on an organization’s network access. Organizations use port scanners to gain insights into possible reconnaissance and attack vectors.

Vulnerability scanners

These scanners can identify known vulnerable misconfigurations and applications running on a system. Vulnerability scanners provide reports that help locate the vulnerabilities threat actors might exploit for initial access.

Network sniffer

A network sniffer monitors network traffic information, such as the origin of the traffic, the device the traffic came from, and the protocol used. It helps monitor data to learn whether it was encrypted to improve security.

Web proxy

A web proxy helps intercept and modify traffic exchanged between a browser and the organization’s web servers. It helps detect HTML features, like hidden form fields, that indicate application vulnerabilities, such as cross-site request forgery (CSRF) and cross-site scripting (XSS).

Password cracker

Threat actors often use password hashing to gain unauthorized access to a target network or system. Password crackers enable organizations to identify weak passwords that might pose a risk of abuse.

Top Open Source Penetration Testing Tools

1. Kali Linux


Kali Linux is a Debian-based Linux distribution for penetration testing and security auditing. This multi-platform solution is freely available under an open source license, providing numerous tools, automation, and configurations to help complete information security tasks efficiently.

It offers industry-specific modifications and over 600 tools for information security tasks, including penetration testing, computer forensics, security research, vulnerability management, red team testing, and reverse engineering.

Kali Linux supports numerous wireless devices and can run properly on various hardware, including many USB devices. Its custom kernel includes the latest injection patches to ensure testers can do wireless assessments.

2. Metasploit

GitHub repo:

License: BSD-3-clause

Metasploit is an open source framework for probing systematic vulnerabilities on servers and networks. Testers can easily customize the framework and use it with most operating systems. A penetration team can introduce Metasploit with custom or ready-made code into a network to probe for weak spots. This information can help address weaknesses and prioritize remediation.

Metasploit includes over 1,677 exploits categorized under 25 platforms, including Android, Python, PHP, Java, and Cisco. It also contains almost 500 payloads, including dynamic payloads for generating unique payloads that can help testers evade antivirus software and static payloads for port forwarding and establishing communications between various networks.

Additionally, Metasploit includes command shell payloads for running random commands or scripts against a host and Meterpreter payloads for commandeering device monitors through VMC to upload and download files or take over sessions.

3. Wireshark

GitHub repo:

License: GNU GPLv2

Wireshark is a popular open source network protocol analysis tool supported by a global organization of software developers and network specialists. The community is active and continues to release updates for new encryption methods and network technologies.

Wireshark is available for Windows and UNIX operating systems and can capture live packet data from a network interface. It can open files containing packet data captured with Wireshark and other programs like tcpdump and WinDump. It lets you import packets from text files that contain hex dumps of packet data and save all captured packet data.

Testers can use Wireshark to display packets with highly detailed protocol information and export specific packets or all packets in various capture file formats. It allows filtering and searching packets using many criteria, colorizing packet displays according to filters, and creating various statistics.

4. w3af

GitHub repo:

License: GPLv2.0

w3af is an open source web application for security scanning commonly used as an attack or audit framework. It provides a vulnerability scanner and various exploitation tools for web applications.

w3af wrapped urllib2 in a thread-safe way with many extensions, such as Keep-Alive, Logging, and Gzip to enable sending custom HTTP requests at lightning speeds. It can inject payloads into almost all parts of an HTTP request.

w3af provides a fuzzing engine that testers can configure using the misc-settings menu. Since not all injections are enabled by default, testers must check the required ones before starting a scan. w3af stores all vulnerabilities and information disclosures identified by one plugin in a knowledge base made accessible to all the other plugins.

5. SQLmap

GitHub repo:

License: GNU General Public License

sqlmap is an open source tool for penetration testing. It can automatically detect and exploit SQL injection flaws and take over database servers. It provides a detection engine with many features for penetration testing and various switches, such as:

  • Database fingerprinting,

  • Accessing an underlying file system,

  • Over data fetching from a database.

  • Executing commands on an operating system using out-of-band connections.

Testers can use sqlmap to set up automatic recognition of various password hash formats and processes for cracking them using a dictionary-based attack. It allows testers to choose between dumping all database tables, a range of entries, certain columns, or a range of characters from each column’s entry.

It supports searching for specific database names, certain tables across all databases, or a certain column across all databases’ tables. It also allows downloading and uploading any file from a database server underlying file system when using MySQL, Microsoft SQL Server, or PostgreSQL.

6. Hashcat

GitHub repo:

License: MIT license

Hashcat is a fast, versatile, and efficient hacking tool commonly used for password cracking by authorized testers and threat actors. It can support brute-force attacks by providing hash values of passwords the tool guesses or applies.

Penetration testers can use Hashcat to uncover compromised and easy-to-guess credentials in a certain environment. Authorized testers often attempt to crack stolen password hashes to move laterally inside the tested network or escalate their privileges to an admin user.

Penetration Testing with BlueVoyant

Today’s security teams need to adopt a proactive approach to protecting client networks, products, and personnel from malicious attacks. BlueVoyant utilizes industry-standard methodologies, focusing on the adversarial mindset to identify vulnerabilities and exploitation vectors to provide clear and concise remediation recommendations.

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