Free course

Linux Server Security Course

Harden and operate an Ubuntu server with controlled SSH access, limited exposure, patched services, useful evidence, tested backups, and a rebuild plan.

5 modules · 25 lessons · No signup

Prerequisites: Security Fundamentals, Linux Basics and Ubuntu VPS

Download this course as PDF or EPUB

Read it offline, on your Kindle, or print it. Join my free newsletter and you get this course plus every other book and course I published.

Download PDFDownload EPUB
~~~

Your progress

of lessons completed.

Course completed.

What you'll learn

Secure a disposable Ubuntu VPS, verify its access and exposure, monitor important changes, restore it, and rehearse compromise response.

Course contents

  1. Secure access

    Threat-model the host and control accounts, sudo, SSH keys, and recovery.

    1. ✓ Threat-model the server
    2. ✓ Use personal admin accounts
    3. ✓ Use SSH keys safely
    4. ✓ Harden SSH without locking yourself out
    5. ✓ Check your understanding: secure access

  2. Network exposure

    Inventory listeners, configure the firewall, terminate TLS, and keep private services private.

    1. ✓ Inventory listening services
    2. ✓ Configure a default-deny firewall
    3. ✓ Terminate TLS deliberately
    4. ✓ Keep private services private
    5. ✓ Check your understanding: network exposure

  3. System hardening

    Patch the system, remove services, restrict processes, and protect configuration.

    1. ✓ Apply security updates
    2. ✓ Disable unneeded services
    3. ✓ Restrict files and processes
    4. ✓ Store server secrets outside code
    5. ✓ Check your understanding: system hardening

  4. Observe and back up

    Read logs, detect drift, create alerts, and prove backups through restores.

    1. ✓ Read authentication and service logs
    2. ✓ Notice unexpected change
    3. ✓ Design actionable alerts
    4. ✓ Back up and restore
    5. ✓ Check your understanding: observe and back up

  5. Respond and rebuild

    Investigate signals, contain the host, rotate credentials, and rebuild from trusted inputs.

    1. ✓ Recognize a possible compromise
    2. ✓ Contain the host
    3. ✓ Rebuild from known-good inputs
    4. ✓ Complete the server security review
    5. ✓ Check your understanding: respond and rebuild