If you’re new to cybersecurity or trying to learn the top cybersecurity tools professionals use, you’re at the right place. We’ll dive into the top 10 information security tools you must learn to build a solid foundation in cybersecurity fundamentals. Tools such as Nessus, nmap, Kali Linux, and Ghidra are all strongly recommended if you’re looking at any career as a Cybersecurity Penetration Tester, Cybersecurity Engineer, or Cybersecurity Analyst. And luckily, almost all of the cybersecurity tools we recommend are open-source and free to use.
Use our table of contents if you’d like to skip to specific tools.
Table of contents
Setting expectations: Cybersecurity technical skills matter
While becoming intimately familiar with all these tools isn’t necessary, having a basic understanding and time testing each out will help immensely. Indeed, one of the contributing factors to challenges in hiring for cybersecurity is that many candidates lack the technical skills necessary for the role. An ISC2 survey in October 2023 found that 44% of surveyed cybersecurity professionals struggled to hire qualified candidates with appropriate technical backgrounds and skill sets. Having the necessary budget to hire top cybersecurity talent is also problematic.
Speaking from personal experience, I found it helpful to learn and try as many tools as possible at the beginning of my cybersecurity journey. From there, you’ll learn what is most interesting to you, and you can go as deep as you wish in that area.
Some of you may find understanding network traffic exciting. In contrast, others may be more inclined to learn about vulnerabilities that exist on the network and how to detect, remediate, and audit them.
Cybersecurity is genuinely a “choose your own adventure” approach, as we all have individual career aspirations or areas of expertise we will develop in time. Whether you eventually find yourself as a Cybersecurity Pre-sales Engineer, supporting Governance, Risk, and Compliance, or as an executive, exposure to tools or concepts will only help you in a competitive market.
Before we begin, an important disclaimer. Any cybersecurity tools listed are to be used in defensive, ethical hacking or on networks that you have explicit, legal, pre-authorized agreements to use. They should never be used on any unauthorized, targeted individuals or networks. Doing so could result in extensive legal charges and potentially jail time. Use of these tools is at your own risk and subject to local laws.
With no further ado, in no specific order, here’s the list:
1) Tenable Nessus
Tenable Nessus (often just “Nessus”) is one of the first tools I learned, and it remains the go-to vulnerability scanner across the cybersecurity industry. It doesn’t matter if you’re working in a lab, production, or even the industrial internet of things – Nessus has expanded vastly in capabilities over the years and remains an infosec tool of choice.
Nessus will detect and report your network environment’s vulnerabilities, display applicable Common Vulnerabilities and Exposures (CVE) information, and provide instructions for remediation. You can adjust the sensitivity of the scans and isolate scans to certain network segments or specific device types. It is enterprise-grade, depending on your license, and is relied upon by top enterprises and governments worldwide.
The Nessus community and support is vast, as it is used across all industries including the U.S. Department of Defense as a program of record, ACAS.
2) Greenbone OpenVAS
Greenbone OpenVAS is the open-source equivalent of Tenable Nessus. While Nessus can create a license for home/lab testing purposes, it has several limitations. It was also created in 2006 and forked from the days of open-source Nessus. OpenVAS has several components, but notably, the OpenVAS Scanner is a full-featured search engine that executes vulnerability tests against target systems.
The Greenbone Community Edition 22.4 also supports deploying OpenVAS in Docker (container) environments.
Like Nessus, OpenVAS has a supported feed that provides daily updates to security vulnerabilities.
3) Nmap / Zenmap
Nmap (“Network Mapper”) is a tool you’ll want to get intimately familiar with whether you’re an aspiring network engineer or a white hat hacker. It has a GUI (Zenmap) and command line interface and has famously been featured in movies such as The Matrix Reloaded, Ocean’s 8, Snowden, Elysium, and The Girl with the Dragon Tattoo. It’s a tool we should all become familiar with at some point in our cybersecurity journey, as it is the de facto best open-source tool for network fingerprinting, discovery, and security auditing.
Want to see what network ports are open? Or what operating system a device is using? Nmap is your tool.
The capabilities of Nmap are utilized in countless other cybersecurity tools. Still, as a beginner, we highly advise getting as comfortable as possible with the original open-source tool – whether it’s the command line or GUI.
4) Wireshark
Wireshark is another free and open-source tool used for network protocol analysis. Do you want to capture network traffic and understand the intricacies of how traffic from your device reaches the public internet? Wireshark will help you understand that. Whenever you hear about “deep packet inspection”, this is it. It is yet another de facto standard in cybersecurity for network protocol analysis and monitoring network traffic.
There are countless uses for Wireshark, but any Network Engineer worth their salt will use Wireshark frequently for packet capture. Wireshark supports live recordings of network traffic or opening a packet capture file for analysis. This is excellent for troubleshooting, gaining a deeper understanding of protocol usage, or device-to-device network traffic.
5) Ghidra
Ghidra is an open-source software reverse engineering toolkit created and maintained by the National Security Agency (NSA). First released to the public in 2019, the toolkit aims to help cybersecurity professionals with reverse engineering and debugging. Formerly classified, it’s become a popular toolkit for malware analysts as it can help find function mappings within widely distributed malware.
Ghidra is built for reverse engineering and file disassembly and is used by cybersecurity professionals and those looking to develop new technical skills in malware analysis. It will support Windows, Linux, and macOS operating systems as a dissembler. Ghidra is written in Java using the Swing framework for the graphical user interface and C++ for the decompiler (the “headless” environment).
Some intended use cases for Ghidra are comparing compiler code, understanding function graphs, and supporting loading multiple binaries simultaneously into a project.
6) Kali Linux
Kali is a powerful, open-source platform for cybersecurity professionals like penetration testers, security researchers, and digital forensic investigators. Think of it as a Swiss Army knife for the digital world, packed with tools for identifying, exploiting, and defending against vulnerabilities.
Kali’s true strength lies in its versatility. Cybersecurity professionals can use it in various ways. Penetration testers can simulate real-world attacks to identify weaknesses in networks and systems. Security researchers can delve into the inner workings of malware and exploit kits to understand their behavior. Digital forensic investigators can use Kali to analyze digital evidence and extract crucial information. And the best part? It’s all open-source, meaning anyone can access and contribute to the platform, fostering a vibrant community of security experts.
It can be deployed easily on various platforms, such as mobile devices, Raspberry Pi, laptops, desktops, or thumb drives. Be aware, however, that Kali has been banned in several countries, such as the United Arab Emirates, and is subject to export controls.
7) Metasploit
Metasploit is an open-source framework that provides a comprehensive database of known vulnerabilities and exploit modules that simulate real-world attacks. Now co-developed with Rapid7, it remains free and is included in other tools such as Kali. These modules replicate how malicious actors might target specific software, operating systems, or network configurations. Imagine it as a digital obstacle course, where security professionals can test their defenses against a wide range of simulated threats.
Metasploit’s capabilities go beyond mere exploitation. It allows penetration testers to craft custom payloads, delivering specific actions once a vulnerability is breached. This could involve stealing data, installing malware, or even taking control of a system. Of course, this all assumes you have the legal permission to do so. Using Metasploit against an unwilling target is illegal and could result in legal charges.
If you want to contribute to Metasploit, visit the official contribution guidelines. Extensive documentation on the official Metasploit website can help quickly learn the framework.
8) Aircrack-ng
Aircrack-ng (or “Aircrack” for short) is a powerful open-source tool for exploiting and hacking wireless networks. It’s a valuable asset for penetration testers and network administrators focused on securing their wireless networks. It packs a punch with monitoring, attacking, testing, and cracking functionalities.
Its most common use case is for capturing and analyzing wireless traffic and cracking weak encryption protocols like WEP and WPA-PSK. If network penetration testing is in scope, Aircrack can be used to launch targeted attacks to expose identified vulnerabilities.
Aircrack cracks weak WiFi passwords using brute-force or dictionary attacks. This highlights the importance of choosing strong, complex passwords for your Wi-Fi network and choosing the strongest encryption protocol available, such as WPA3.
To learn more about Aircrack, visit the official Wiki and GitHub repository.
9) Cain and Abel
Cain and Abel (often just “Cain”) is a powerful and complex tool used for various use cases. Ethical hackers and penetration testers can leverage Cain to simulate real-world attacks, assess network security, and identify exploitable vulnerabilities before malicious actors can. It can also be used to intercept and poison ARP and DNS caches, record VoIP communications, and crack passwords.
For example, if network traffic uses unencrypted protocols, Cain can capture the traffic, potentially revealing usernames and passwords transmitted in plain text. This highlights the importance of using secure connections like HTTPS whenever possible. Cain can also analyze wireless networks, uncovering weaknesses in encryption and potentially even capturing handshake packets to crack WiFi passwords (again, highlighting the need for strong WPA3 encryption).
The official Cain website has been taken down, so accessing a “clean” copy of the tool can be challenging. You can download Cain and Abel for Windows from the Archive.org Wayback Machine cache of the original website.
10) Snort
Snort is an open-source intrusion detection and prevention system (IDS/IPS) capable of real-time traffic analysis and packet logging. Initially created in 1998 by Marty Roesch, founder and CTO of SourceFire, Snort remains open-source. Cisco acquired the rights to Snort and SourceFire in 2013 and has integrated Snort capabilities across its cybersecurity platforms. Often forgotten today, Snort remains a powerful yet simple and easy-to-learn tool for cybersecurity professionals, even in 2024.
Snort provides three core capabilities: traffic analysis, rule-based detection, and real-time protection. As an IDS/IPS, one of Snort’s popular use cases is for detecting TCP timestamp values. Manipulating timestamps is a popular technique when cybercriminals breach into networks and manipulate logs to erase digital footprints – or throw off forensic efforts.
This is valuable knowledge for an intrusion detection system (IDS) or intrusion prevention system (IPS) to possess and implement to avoid evasions that employ TCP timestamp value mutations.
You can start with Snort by downloading the installer from the official GitHub repository or cloning it into your working environment. Snort rules and plugins are powerful extensions of the platform that speak to its relevance over 25 years later.
