Path 03: Operating Systems & Linux — KashSec Academy

Install Kali in VirtualBox, then a full tour of the Linux command line. 26 free lessons, beginner level, starting with "What is an operating system?"

Level: Beginner · 26 lessons · Free, no account needed.

Lessons in this path

  1. What is an operating system? — The manager that runs your computer.
  2. Windows vs Linux vs macOS — The big three, and why security loves Linux.
  3. Why hackers love Linux — Open, scriptable, and the tools live here.
  4. Choosing a Linux distro for security work — Kali vs. Parrot vs. Ubuntu — attack platform vs. target system.
  5. What is virtualization? — A whole computer inside your computer.
  6. Install VirtualBox — Step-by-step with troubleshooting.
  7. Install Kali Linux — The pre-built image route, safely.
  8. Snapshots & safety — Undo mistakes; network isolation.
  9. Meet the terminal — Your first commands, unafraid.
  10. The Linux Filesystem Hierarchy — Why /etc matters most, and how /tmp becomes an attack surface.
  11. Files & folders — Navigate, read, search — grep is gold.
  12. Text Processing Tools: Beyond grep — sed, awk, cut, and sort — chained together with pipes.
  13. Users, permissions & sudo — Read rwx, install with apt, the SUID clue.
  14. Linux Package Management — apt/dnf/pacman, repositories, and why package signing matters.
  15. Linux Process Management — ps, top, kill, and systemd — the Linux side of Path 07's Task Manager coverage.
  16. Linux Networking Commands — ip, ss, curl, and a first, careful preview of nmap.
  17. SSH & Remote Access — Key-based auth, hardening, and the Linux parallel to Path 07's RDP lesson.
  18. Linux Cron & Scheduling — Scheduled jobs, and why cron is a favorite persistence mechanism.
  19. Linux Logging Basics — /var/log, journalctl, and why attackers try to clear their tracks.
  20. Linux Firewall Basics — iptables, ufw, and applying default-deny without locking yourself out.
  21. Your first bash script — Pipes, redirection, loops — automation begins.
  22. Shell Scripting Security Pitfalls — Command injection, unquoted variables, and eval's real dangers.
  23. A Practical Linux Hardening Checklist — Every earlier lesson in this path, consolidated into one ordered checklist.
  24. Linux Careers & Certifications — Linux+, RHCSA, and why this foundation underlies most other security paths.
  25. Advanced Terminal Lab — Level up your command line skills.
  26. Linux Forensics Basics Lab — Learn to investigate a Linux system.