Free Cybersecurity Resources

I will try to keep this list continuously updated with training and informational resources for different areas that could benefit students and professionals of cybersecurity and IT.

Systems Administration

Core Systems Concepts

→Storage
→CPU
→Memory
→Boot procedure
→System internals
→Core directories
→Filesystem hierarchy
→Windows Registry
→Event and audit logs

Shells & Terminals

Unix-like Shells

shbashzshfishkshtcshpwsh

Windows Shells

powershellcmd

Common Command Line Operations

Create, delete, modify files and directories

lsmkdircdtouchcpmvrmvimnanoGet-ChildItemNew-ItemCopy-ItemMove-ItemRemove-Item

Manipulating file contents and text streams

grepcatsedawktrcutpaste-split-replace-join

Managing processes and services

pskillsystemctlservicestraceGet-ProcessStop-ProcessGet-ServiceRestart-Service

Installing packages

aptyumpacmanwingetInstall-PackageUninstall-Package

Downloading files

wgetcurlInvoke-WebRequestInvoke-RestMethod

Computer Networking

Core Networking Concepts

→IP addressing
→Subnetting
→Routing (ping, layer 3)
→Switching (ARP, layer 2)
→Firewalls
→TCP/UDP protocols & ports
→VLANs
→Tunnels
→Proxies
→DNS
→OSI model
→TCP/IP model

Networking Tools

IP Configuration

ip addressip neighboripconfigGet-NetIPAddressGet-NetAdapter

Host Discovery

pingarp-scannmap

Packet Capture & Analysis

Wiresharktsharktcpdump

Sockets

netcatsocatnetstatss

DNS Troubleshooting

nslookupdigResolve-DnsNameDNS DumpsterMXToolbox

Remote Connectivity

sshscpOpenVPNWireGuard

Free Networking Courses

→Computer Networking: A Top-Down Approach — Textbook (free PDF) →Networking for Web Developers — Udacity →How DNS works — YouTube →What is the OSI Model — freeCodeCamp →TLS Handshake Explained — Cloudflare →Subnetting Practice — SubnettingPractice.com

From This Site

→How Cloudflare Works: A Security Blueprint →Network Forensics and Full Packet Capture →Network Security Monitoring with Suricata

Web

Core Web Concepts

→HTTP methods and headers
→Web servers
→Proxies
→Directories and files
→HTML / CSS / JavaScript
→Databases and SQL
→Inputs and parameters
→Authentication and sessions
→APIs and REST

Web Security Tools

HTTP Inspection & Tampering

Burp SuitemitmproxyCaidoZAP

Content Discovery

gobusterferoxbusterffufdirbuster

Web Stack Analyzers

WappalyzerWhatWebWeb Check

Brute Force

hydraffufmedusa

Web Resources

→Web Security Academy — PortSwigger (Free) →OWASP Top 10 — Web application security risks →HTTP request methods reference — MDN →Learn HTML interactively — Codecademy →Learn JavaScript interactively — Codecademy →Exploit Database — OffSec →Google search operators reference — Kinsta

Computer Programming

Core Programming Concepts

→Data types and variables
→Flow logic (if/else)
→Loops
→Functions
→Object-oriented programming (OOP)
→Source code review
→Modifying exploits
→Scripting and automation

Languages Worth Learning for Security

Scripting (start here)

PythonBashPowerShellJavaScript

Compiled

CC++GoRust

Free Programming Training

→Learn Python interactively — learnpython.org →Intro to Python — Udacity →Learn shell scripting — shellscript.sh →Learn PowerShell through challenges — UnderTheWire →Multi-language coding exercises — Exercism.org →Competitive coding challenges — Codewars →Online coding tests — HackerRank

Cybersecurity

Offensive Security

Practice Platforms

→TryHackMe — Best for beginners, guided and structured →Hack The Box — Intermediate to advanced machines →PortSwigger Web Security Academy — Web security labs →PicoCTF — Beginner CTF challenges from Carnegie Mellon →OverTheWire — Linux and security wargames →PentesterLab — Web application penetration testing →247CTF — Hacking challenges across multiple categories →Proving Grounds — OffSec official practice →pwn.college — Challenges spanning wide security topics →Hacker101 CTF — CTF challenges by HackerOne →PWNED LABS — Cloud security challenges

Cheat Sheets & References

→HackTricks — Extensive hacking tips and techniques →GTFOBins — Linux binary abuse reference →LOLBAS — Windows binary abuse reference →RevShells — Reverse shell generator →PayloadsAllTheThings — Payload and bypass reference →pentestmonkey — Reverse shell cheat sheet →Active Directory Exploitation Cheat Sheet →The Hacker Recipes — Red teaming tips and tricks

From This Site

→Snort IDS: Installing and Configuring Snort →OSINT Fundamentals →Penetration Testing Basics →Deploying Vulnerable Applications

Defensive Security

Practice Platforms

→Blue Team Labs Online — Defensive security challenges →CyberDefenders — Interactive blue team training →LetsDefend — SOC analyst training and simulations →Splunk Free Training — SIEM fundamentals →Hack The Box Academy — Learn and practice cybersecurity

Defense Frameworks

→MITRE ATT&CK — Adversary tactics and techniques →MITRE Engage — Adversary engagement framework →NIST Cybersecurity Framework →Lockheed Martin Cyber Kill Chain →OWASP Top 10 — Web application security risks

Cheat Sheets & References

→SANS Blue Team Operations →Threat Hunting with MITRE ATT&CK →GitHub — Blue team tools and resources →GitHub — System hardening resources

From This Site

→Getting Started with Splunk →Splunk: MITRE ATT&CK and Behavioral Mapping →Incident Response Automation in the Home Lab →Network Forensics and Full Packet Capture

Security Awareness

Cybersecurity isn't just for professionals. Everyone benefits from understanding how to stay safe online.

→Phishing and Email Security — 0xBoderebe →Password Security — 0xBoderebe →Identity Theft Protection — 0xBoderebe →Mobile Security — 0xBoderebe →Safe Browsing — 0xBoderebe →Social Engineering — 0xBoderebe →Have I Been Pwned — Check if your data was breached →CISA Free Cybersecurity Resources

Certifications

Certifications validate your skills and open doors. Here are the most recognized paths with free study resources where available.

→CompTIA Security+ — Most recognized entry-level cert →CompTIA Network+ Free Study — Professor Messer →ISC2 CC — Free entry-level cybersecurity certification →Google Cybersecurity Certificate — Coursera (free to audit) →eJPT by INE — Practical entry-level penetration testing cert →TCM Security Certifications — Practical penetration testing and security certifications →MITRE ATT&CK Defender — Free ATT&CK training and cert

News & Threat Intelligence

Stay current with the threat landscape. These are the sources worth checking regularly.

→Krebs on Security — In-depth security investigations →The Hacker News — Daily cybersecurity news →BleepingComputer — Breaking security news →Dark Reading — Enterprise security news →CISA Advisories — Official US government threat alerts →CVE Database — Common vulnerabilities and exposures →VirusTotal — Free malware and URL scanner →Shodan — Search engine for internet-connected devices

From the Community

Sorted alphabetically and not by any specific preference.

Free Cybersecurity Resources

Systems Administration

Core Systems Concepts

Shells & Terminals

Common Command Line Operations

Cheat Sheets

Free Linux Training

Free Windows Training

Computer Networking

Core Networking Concepts

Networking Tools

Free Networking Courses

From This Site

Web

Core Web Concepts

Web Security Tools

Web Resources

Computer Programming

Core Programming Concepts

Languages Worth Learning for Security

Free Programming Training

Cybersecurity

Offensive Security

Practice Platforms

Cheat Sheets & References

From This Site

Defensive Security

Practice Platforms

Defense Frameworks

Cheat Sheets & References

From This Site

Security Awareness

Certifications

News & Threat Intelligence

From the Community

More from 0xBoderebe

Cybersecurity Foundation: A Practitioner's Guide

Cybersecurity HomeLab Series

Security Awareness Guides