Linux Security and Hardening 8hours

Linux is a popular operating system that is known for its security and performance. However, it has been found that Linux still has a long way to go when it comes to security and hardening.

Chapter 1 : Linux in a Virtual Environment

Linux is a platform that enables users to use their computing power and resources in a virtual environment. It has been widely adopted as a server operating system.

Security breaches and News

Virtualbox and Cygwin

Linux System update


Chapter 3 : Securing Your Server with a Firewall

A firewall is a software or hardware system that controls which network packets are allowed to enter or exit the computer.

An overview of firewalld

An overview of iptables

Uncomplicated firewall


firewalld for Red Hat systems


Chapter 4 : Encryption Technologies

Encryption technologies are usually used to conceal data or information. It is often used alongside other information security solutions like firewalls, anti-virus programs, and intrusion detection systems.

GNU Privacy Guard (GPG)

Encrypting partitions

Encrypting directories

Using VeraCrypt for cross-platform

OpenSSL and the public key infrastructure


Chapter 6 : Mastering Discretionary Access Control

Discretionary access control is a feature of Active Directory that can be used to set permissions on objects and users. It allows you to make changes to objects and user permissions without affecting other objects and users.

Using chown to change ownership of files and directories

Using chmod to set permissions on files and directories

Using SUID and SGID on regular files

Security implications of the SUID and SGID permissions

Using extended file attributes to protect sensitive files

Securing system configuration files


Chapter 9 : Kernel Hardening and Process Isolation

Kernel hardening is a technique of making an operating system resistant to attacks from a computer virus or a hacker. Process isolation is a process management technique that enables an application to run in its own protected environment and limits the impact of other applications on the application.

Understanding the /proc filesystem

Setting kernel parameters with sysctl

Configuring the sysctl.conf file

Understanding process isolation


Chapter 11 : Logging and Log Security

To prevent any unwanted intrusions, some webmasters are now using log monitoring software to monitor their logs for suspicious activity which could be an indication of a potential hacking attempt.

Understanding the Linux system log files

Understanding rsyslog

Understanding journald

Making things easier with Logwatch

Setting up a remote log server


Chapter 12 : Vulnerability Scanning and Intrusion Detection

It’s important to have both vulnerability scanning and intrusion detection systems in place in order for your company to keep your data safe.

Snort and Security Onion

IPFire and it’s built-in (IPS)

Scanning and hardening with Lynis

Finding vulnerabilities with OpenVAS

Web server scanning with Nikto


Chapter 13 : Security Tips and Tricks

Security is a concern in a digital world. You can protect yourself from digital threats by following the security tips and tricks.

Auditing system services

Password protecting the GRUB 2 bootloader

Securely configuring BIOS/UEFI

Using a security checklist for system setup


Satish Kumar

Kumar Satish


Kumar Satish started his career as a Unix and Linux System Engineer in 2011. Kumar has professiona experience with CentOS, RedHat, Ubuntu, and Debian. He enjoys teaching others how to use and exploit the power of the Linux operating system.