Get Linux: A Beginner’s Guide to Installing Your First Distro

Get Linux Securely: Tips for Safe Installation and UpdatesSwitching to Linux is a great way to regain control of your computing, improve privacy, and avoid vendor lock-in. Security, however, requires more than just choosing a distribution — it begins with how you obtain and install the system and continues through careful configuration and regular maintenance. This article walks through practical, hands-on advice to help you “get Linux securely,” from selecting a trustworthy distro to setting up updates and hardening the system.

1. Choose a trustworthy distribution and download sources

• Pick a distribution with an active community, timely security updates, and a clear release model. Good choices for general use include Ubuntu LTS, Debian, Fedora, openSUSE Leap/Tumbleweed, Linux Mint, and privacy-focused options like Tails or Qubes OS for threat-model specific use cases.
• Download ISOs only from official distribution websites or verified mirrors. Avoid third-party hosts unless recommended by the distro project.
• Verify downloads by checking signatures and checksums:
  • Many projects publish a SHA256 or SHA512 checksum alongside the ISO. After download, compute the checksum locally and compare.
  • For stronger assurance, verify the GPG signature of the release using the distro’s release signing key:
    1. Import the distro’s public key into your GPG keyring.
    2. Verify the ISO’s .sig or .asc signature file.
  • If you’re unfamiliar with GPG verification, read the distribution’s verification guide — it’s usually straightforward and critical for avoiding tampered images.

2. Prepare installation media safely

• Use reliable hardware: a good-quality USB flash drive from a reputable brand lowers the chance of data corruption.
• Create the bootable media using trusted tools:
  • GUI tools: Etcher, Rufus (Windows), or GNOME Disks.
  • Command-line: use dd carefully (double-check device path) or cp on some systems.
• After flashing, re-check the USB device’s contents or checksum if your tool supports it to ensure the image burned correctly.
• If using UEFI, disable Secure Boot only if the distribution doesn’t support it. Many modern distros provide signed bootloaders compatible with Secure Boot.

3. Installation best practices

• Backup first: before resizing partitions or replacing an OS, make a full backup of important files. Use external drives or cloud backups you trust.
• Use full-disk encryption if you need confidentiality:
  • LUKS is the standard choice on Linux for encrypting partitions.
  • During installation, select the “encrypt my disk” or manual LUKS setup.
  • Use a strong passphrase (long, unique, and not easily guessable). Consider using a hardware token or a password manager to store recovery keys.
• For dual-boot setups:
  • Install Linux after Windows to make GRUB installation smoother, or be prepared to restore bootloaders.
  • Consider creating separate encrypted home partitions rather than sharing /home with another Linux install.
• Keep network off during initial setup when possible, or use a firewall to limit exposure until you’ve applied updates.

4. Post-install hardening (first 24–48 hours)

• Update the system immediately:
  • Use your package manager (e.g., sudo apt update && sudo apt upgrade, sudo dnf upgrade, sudo zypper update) to install security patches.
• Create a non-root daily user and use sudo for administrative tasks. Disable direct root SSH login if you enable SSH.
• Enable a firewall:
  • Use uncomplicated firewall tools like ufw (Ubuntu) or firewalld (Fedora/RHEL/openSUSE).
  • Start with a default deny policy for incoming connections and explicitly allow needed services.
• Secure SSH:
  • If you need remote access, prefer SSH key authentication and disable password authentication in /etc/ssh/sshd_config.
  • Change the default SSH port only as an obfuscation (not a real security measure), and consider tools like fail2ban or sshguard to block brute-force attempts.
• Remove unnecessary services and packages: fewer services mean a smaller attack surface. Audit systemctl list-unit-files --state=enabled and disable what you don’t need.
• Install and configure an automated update tool if you prefer automatic security updates (e.g., unattended-upgrades on Debian/Ubuntu).

5. Keep the system updated and monitor for security advisories

• Regularly apply updates — many distributions publish security advisories and RSS feeds for critical patches.
• Use distribution tools or third-party services to monitor CVEs relevant to installed packages. For enterprise or advanced personal setups, consider:
  • Canonical’s Livepatch (for Ubuntu kernel hotpatching),
  • Automatically applied security-only repos (where available),
  • Tools like apt-listchanges to see what updates include.
• Verify the integrity of critical system files with tools like AIDE or tripwire if you need high assurance of tamper detection.

6. Software sources and package management safety

• Prefer distribution repositories and flatpak/snaps from trusted stores (Flathub, Snap Store) over random third-party repositories.
• If adding third-party repos (PPAs on Ubuntu or vendor repos), ensure they are reputable and remove them when no longer needed.
• Use package signing: distribution package managers verify signatures automatically when repos are configured correctly — don’t disable signature checks.

7. Browser, email, and user-space app security

• Use modern, sandboxed app formats where possible: Flatpak isolates GUI apps better than traditional packages in many setups.
• Harden your browser:
  • Keep it up to date.
  • Use privacy/security extensions sparingly (adblocker, HTTPS Everywhere-like functionality, script blockers).
  • Consider using containerized browser profiles for risky activities (or a dedicated VM).
• Be cautious with email attachments and office macros; treat unknown files as potentially malicious.

8. Privacy-oriented configurations

• Minimize telemetry: some distributions and apps collect optional usage data. Disable telemetry where possible in settings.
• Use system-wide DNS privacy (DNS-over-HTTPS or DNS-over-TLS) via system resolvers or tools like cloudflared or stubby.
• For stronger privacy/anonymity needs, consider Tails (VM/live-only) or Qubes OS (compartmentalization).

9. Advanced protections

• Use disk and file-system snapshots (Btrfs or LVM snapshots + backups) to quickly recover from ransomware or misconfiguration.
• Consider application sandboxing: Firejail or bubblewrap can add isolation for GUI and CLI apps.
• Use hardware-backed security:
  • TPM for secure boot and disk encryption integration.
  • YubiKey or other hardware tokens for SSH key storage and two-factor authentication.
• For high-risk threat models, isolate sensitive activities in VMs or a separate physical machine.

10. Backups and recovery plans

• Regular, automated backups are essential. Follow the 3-2-1 rule: at least three copies, on two different media, with one offsite.
• Test recovery: a backup is only useful if you can restore it. Periodically verify backups.
• Keep recovery tools handy: a live USB with rescue tools, copies of LUKS headers (if using LUKS), and documented recovery steps.

11. Common mistakes to avoid

• Skipping verification of downloaded ISOs — this invites tampered images.
• Using weak encryption passphrases or not encrypting sensitive disks.
• Installing unnecessary third-party software or random PPAs without vetting.
• Neglecting updates — many successful attacks exploit unpatched systems.
• Relying solely on obscurity (changing ports, hiding services) rather than proper hardening.

12. Quick secure-setup checklist

• Verify ISO checksum and GPG signature.
• Write ISO to a reliable USB tool and re-check.
• Backup data before installing.
• Enable full-disk encryption (LUKS) if needed.
• Update immediately after install.
• Create a non-root user and disable root SSH login.
• Enable and configure a firewall.
• Use SSH keys and fail2ban for remote access.
• Subscribe to distro security announcements.
• Implement automated backups and test restores.

If you want, I can provide a step-by-step walkthrough for a specific distribution (Ubuntu, Fedora, Debian, or Qubes) including terminal commands and example configuration files.