Top Network Penetration Testing Tools

Table of Contents

Penetration testing, or “pentesting” is the process of testing a computer system, network, or web application to find security vulnerabilities that an attacker could exploit. Pentesters use a variety of tools to identify and exploit these vulnerabilities through penetration testing. In this blog post, we will present the top, well-known network penetration testing tools on the market, from Kali Linux and Nessus to Ettercap and SSLScan. The objective is to give you a quick overview of each tool, highlighting what it is, what it does, and what are some of its key benefits.

Kali Linux

Kali Linux is one of the most popular penetration testing operating systems with over 600 tools for penetration testing and security analytics, including Nmap, Metasploit, Burp Suite, and John the Ripper. However, it is important to note that Kali Linux is designed for offense, not defense, and can be easily exploited if not used correctly. Kali Linux is a Debian-based Linux distribution aimed at advanced penetration testing and security auditing. Kali Linux is available in several editions, can be run on physical computer systems or virtual machines, and also be installed on some routers and embedded devices.


Nmap, designed for exploring a target network or system, contains a wealth of built-in knowledge on a variety of scan types, including stealth scans, SYN scans, and UDP scans. Its interface Zenmap, a point-and-click type, is highly usable and configurable for performing basic scans. In the end, the scan result, both textual and visual, outlines the detected systems and ports along with the protocols identified. As a powerful and versatile tool for penetration testing, Nmap also includes several features for evading defenses or detecting unique features and identifying particular operating systems or applications.


Metasploit, combining automated scans and individual manual attack tools, is a great tool for penetration testers. The paid version is worth the money if you need the extra features. However, many penetration testers seem to get by with the free open-source version, Metasploit Framework. The paid version, Metasploit Pro, offers more automation features, including a graphical user interface, system auditing, reporting services, web application scanning, and the Network Discovery feature. Both versions come with a vulnerability scanner covering more than 1,500 vulnerabilities, as well as a command-line option called Metasploit Console.


As a famous and effective cross-platform vulnerability scanner, Nessus proves an essential tool for any penetration tester. It provides not only extensive vulnerability scanning capabilities, but also information on exploitation and remediation for identified vulnerabilities. As a tool available from Tenable under multiple licensing models, Nessus is chiefly used for its extensive library of vulnerability signatures allowing the identification of potential attack vectors. Unlike the commercial versions, the free version of Nessus limits the number of IPs that can be scanned. Nessus has pre-built policies and templates for auditing and patching all sorts of IT and mobile assets, as well as customizable reports and automatic offline vulnerability scans.


Penetration Testing Buyer's Guide

Everything You Need to Know

Gain confidence in your future cybersecurity assessments and make informed decisions.
This field is for validation purposes and should be left unchanged.


Wireshark provides a large number of built-in protocol dissectors, which enable it to identify a range of different types of network traffic and break it down into an easily readable format. The Wireshark GUI labels each field of a network packet and provides built-in traffic coloring, filtering, and connection following, thus helping penetration testers identify packets of interest. At its core, Wireshark is much more than just a great packet dissector, offering a large number of built-in functionality for network traffic analysis and being extensible for custom traffic analysis. Wireshark proves an invaluable penetration testing tool to easily and rapidly extract features of interest from a network traffic capture.

John the Ripper

As a highly flexible and configurable tool for cracking passwords, John the Ripper (JTR) is designed primarily for use on CPUs. However, it also supports GPUs for faster cracking. John the Ripper supports all of the most common cracking techniques, including brute-force, dictionary, and hybrid attacks. Additionally, it has a large library of supported hash formats. Users can specify unique combinations of hash functions and generate custom candidate password formats for dictionary attacks. By doing so, penetration testers can optimize JTR to crack passwords more effectively.


As the Suite version, Hashcat is one of the fastest password recovery tools to date with a word generator and a password cracking element. Among the fully-supported modes are dictionary, combination, brute-force, rule-based, toggle-case, and hybrid password attacks. Best used for up-and-coming pentesters or system recovery specialists looking for the best password recovery tool, Hashcat also benefits from a great online community providing support for patching, a wiki page, and walkthroughs. As penetration testing often involves exfiltration of hashed passwords, a tool like Hashcat can also be used to guess or brute-force passwords offline.


When you need to crack a password online, namely an SSH or FTP login, IMAP, IRC, RDP, and many more, John the Ripper’s companion, Hydra, can come in handy. Simply point Hydra at the service to be cracked, even submitting it a word list, then let it execute. Rate-limiting password attempts and disconnecting users after a series of login attempts are effective defensive mitigations against attackers, and tools like Hydra will prove a great reminder of that. Hydra is the only password pentesting tool supporting both multiple protocols and parallel connections, allowing it to attempt cracking numerous passwords on various systems simultaneously without losing connection.


Ettercap is a great tool for penetration testers to hijack all of the routings on communications for all of the endpoints on a network or only one. The attack capabilities of this tool are great, making up for its out-of-date terminal/command prompt screen interface. Ettercap also facilitates masquerading and packet injection. To use this tool, penetration testers must be already inside the network they are targeting as Ettercap works by hijacking the system of the network in traffic sent to a specific endpoint. With its ARP poisoning used to divert traffic, Hascat can be used as well for Denial-of-Service, man-in-the-middle, and DNS hijacking attacks.


OpenVAS, an open-source vulnerability scanner by Greenbone Networks, is chiefly used to identify security issues in systems and network infrastructures, but also to scan for vulnerabilities in a variety of systems, including web applications, databases, operating systems, and network devices. OpenVAS can be used to perform penetration testing, vulnerability assessments, and security audits. OpenVAS also features a regularly updated community feed including more than 50,000 vulnerability tests. Network administrators, vulnerability scanners, and penetration testers can use its client-side for configuring scans and viewing reports. As ab all-in-one scanning tool, OpenVAS provides search capabilities for over 26,000 CVEs.


Scapy is a powerful Python interpreter for creating, forging, decoding, capturing, analyzing, and dissecting packets on the network. Allowing you to also inject packets into the network, Scapy supports a large number of network protocols and can handle or manipulate wireless communication packets. Scapy can get the job done by many other network tools, including Nmap, hping, arp-scan, and Tshark (the Wireshark command line). Scapy’s baseline concept is being capable of sending and receiving packets and also sniffing packets. The packets to be sent can be easily created by the built-in options while the received packets can be dissected. The sniffing of packets helps understand the communication that is taking place over the network.


Providing low-level programmatic access to the packets and implementing some protocols, Impacket is a powerful tool that allows users to construct packets from scratch and parse raw data. With its object-oriented API, Impacket makes it easy to work with deep hierarchies of protocols. Its library also provides a set of tools as examples of what can be done with it. The Impacket library includes a collection of python scripts that prove highly useful for security professionals in various attack scenarios. Among other things, Impacket tools are used to attack Domain Controllers in Active Directory (AD) environments.


As a tool for searching devices connected to the Internet, Shodan helps you gather information on desktops, servers, IoT devices, and more. This information includes metadata, namely the software running on each device. Some of the common uses of Shodan are network security, market research, cyber risk, as well as scanning IoT devices and tracking ransomware attacks. As the prime search engine used by hackers to identify exposed assets, Shodan provides the results that are more relevant security professionals. This open-source tool mostly helps security professionals identify targets and then test them for different vulnerabilities, passwords, services, ports, and the like.


As the swiss-army knife for debugging, testing, privacy measurements, and penetration testing, Mitmproxy can be used for intercepting, inspecting, modifying, and replaying web traffic such as HTTP/1, HTTP/2, WebSockets, or any other SSL/TLS-protected protocols. You can also prettify and decode a variety of message types, ranging from HTML to Protobufs. Mitmproxy works as a man-in-the-middle, pretending to be the server to the client and vice versa, decoding traffic, generating on-the-fly certificates to fool the client into believing that they are communicating with the server. While other proxies usually focus on filtering content or caching it for speed optimization, Mitmproxy aims to let an attacker monitor, capture, and alter connections in real-time.


Among the most common penetration testing tools used as a first attempt to break into a Windows network, Responder has gained popularity among ransomware enterprises seeking to compromise the greater number of Windows network accounts possible.  Responder is a Python tool capable of harvesting credentials through Man-in-the-Middle (MiTM) attacks in the Windows network environment. It does so by making use of Windows default name resolution protocols and rogue servers. Among the protocols exploited by the tool are LLMNR, NBT-NS, and MDNS. Responder replies to the targeted user’s computer with fake responses, retrieving usernames and password hashes in the process. Responder can also retrieve passwords in cleartext.


As a command-line tool, SSLScan performs a large variety of tests over the specified target and then returns a comprehensive list of the protocols and ciphers accepted by an SSL/TLS server, in addition to some other information that proved useful in cybersecurity testing. SSLScan can check all ciphers, protocols, or key strengths, and report all secure and insecure services. SSLScan is best suited for mitigation purposes and self-verifications. Some key vulnerabilities checked by SSLScan include Heartbleed, SSLV2, SSLV3, low-bit ciphers, as well as unsupported ciphers and certificates.

Wrapping up

Network penetration testing tools are essential for improving the integrity, resilience, and security of your external networks, and we’ve outlined here some of the most popular, effective, and well-known tools used by professional pentesters. Understanding these tools can be a great starting point in your exploration of network penetration testing and how it can help secure your networks.

If you need help securing your networks, contact us today.

Subscribe to Our Newsletter!
Stay on top of cybersecurity risks, evolving threats and industry news.
This field is for validation purposes and should be left unchanged.

Share this article on social media:

Recent Blog Posts

Featured Services


The Latest Blog Articles From Vumetric

From industry trends,  to recommended best practices, read it here first:



Everything You Need to Know

Gain confidence in your future cybersecurity assessments by learning to effectively plan, scope and execute projects.


Enter your Email Address

This field is for validation purposes and should be left unchanged.

* No free email provider (e.g:,, etc.)

This site is registered on as a development site. Switch to a production site key to remove this banner.