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

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What you'll learn

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

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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