linux-security - ITNotes

Linux Incident Response: 6 Months of Battle-Tested Survival Tactics

April 4, 2026

A battle-tested Linux incident response workflow. Learn how to use busybox-static and auditd to detect server breaches and handle high-pressure forensic investigations.

Security

Stop the Guesswork: Using Auditd for Linux Incident Response

March 30, 2026

Move beyond basic Linux logging. This guide shows you how to use Auditd to track file modifications and command execution at the kernel level to solve production incidents faster.

Security

Linux File Integrity Monitoring: Catching Stealthy Changes with AIDE

March 30, 2026

Learn how to use AIDE (Advanced Intrusion Detection Environment) for File Integrity Monitoring on Linux. This guide covers setting up a baseline database, detecting unauthorized changes, and automating security reports.

Security

Mastering OpenVAS/Greenbone: A Practical Guide to Vulnerability Management

March 24, 2026

After experiencing relentless SSH brute-force attacks, I recognized the critical need for proactive security. This guide introduces OpenVAS/Greenbone as a robust, open-source solution for comprehensive vulnerability management, covering practical setup, scanning, and report analysis to keep your systems secure.

Linux

Linux Security Hardening with SELinux: A Deep Dive from Basics to Advanced Policies

March 20, 2026

SELinux offers robust Linux security, but its complexity demands a careful approach. This tutorial covers comparing security models, pros and cons after production use, recommended setup, and a detailed implementation guide for basic to advanced SELinux configuration.

Linux

How to Secure SSH Server: Disable Root Login and Set Up Key-Based Authentication

March 15, 2026

Default SSH configuration leaves your server exposed to brute-force attacks. This guide walks through disabling root login, setting up key-based authentication, and validating your SSH hardening configuration on Ubuntu/Debian servers.

Security

How to Set Up a Firewall with UFW / iptables for Linux Server Security

March 12, 2026

My server recently survived an intense SSH brute-force attack, reinforcing the urgent need for strong security. This tutorial walks you through setting up UFW, the Uncomplicated Firewall, to defend your Linux server from unauthorized access. Learn to configure crucial rules and maintain a secure system.

Security

SSH Security Best Practices: Key Auth, Fail2Ban, and Port Knocking Explained

March 11, 2026

Discover how to significantly enhance your server's SSH security. This tutorial covers implementing key authentication to replace passwords, using Fail2Ban to combat brute-force attacks, and setting up port knocking for an invisible SSH port, protecting your server from unauthorized access.

Linux

Linux chmod and chown: What 3 Years of Managing 10+ VPS Taught Me About Permissions

March 6, 2026

After managing 10+ Linux VPS instances over 3 years, I've seen sysadmins take two very different approaches to chmod and chown — and only one holds up under pressure. Here's the full breakdown: what works, what backfires, and the exact permission model I apply to every new server.