Linux guides
9 guides in Security & Hardening · beginner.
Install KeePassXC for Local Password Management
Install KeePassXC on Linux, create an encrypted database, set up browser autofill, SSH agent, secret service, and YubiKey two-factor unlock.
Use pass — the UNIX Password Manager
Set up pass, the UNIX password manager: initialise a GPG-encrypted store, manage credentials, sync across machines with Git, and integrate with your browser.
Encrypt Files with age and rage
Learn to encrypt and decrypt files with age and rage: generate keys, encrypt for multiple recipients, use SSH keys, and integrate with the passage password manager.
Protect SSH against Brute-force with fail2ban
Install and configure fail2ban to automatically block SSH brute-force attacks using jails, custom ban times, allowlists, and the recidive jail.
Manage SSH Keys and the SSH Agent
Generate ed25519 and RSA SSH keys, manage passphrases with ssh-agent and keychain, forward credentials safely, and harden with FIDO2 hardware tokens.
How to Scan a Linux System for Malware with ClamAV
Install ClamAV on Linux, update virus signatures with freshclam, run on-demand and scheduled scans, and verify detection works with the EICAR test file.
Shadow Passwords Explained
Learn why /etc/shadow exists, how to read its nine fields, which hashing algorithms are current, and how to manage password aging with chage, pwconv, and pwck.
How to Set Up a Firewall with UFW
Learn to configure UFW on Linux: set secure default policies, open only the ports you need, read existing rules, and verify your firewall is working correctly.
How to Enable Automatic Security Updates
Enable automatic security updates on Debian, Ubuntu, Fedora, and RHEL using unattended-upgrades and dnf-automatic — configured to patch safely without manual effort.