Book Image

Mastering Linux Security and Hardening

By : Donald A. Tevault
Book Image

Mastering Linux Security and Hardening

By: Donald A. Tevault

Overview of this book

This book has extensive coverage of techniques that will help prevent attackers from breaching your system, by building a much more secure Linux environment. You will learn various security techniques such as SSH hardening, network service detection, setting up firewalls, encrypting file systems, protecting user accounts, authentication processes, and so on. Moving forward, you will also develop hands-on skills with advanced Linux permissions, access control, special modes, and more. Lastly, this book will also cover best practices and troubleshooting techniques to get your work done efficiently. By the end of this book, you will be confident in delivering a system that will be much harder to compromise.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface

Controlling the auditd daemon


So, you have a directory full of super-secret files that only a very few people need to see, and you want to know when unauthorized people try to see them. Or, maybe you want to see when a certain file gets changed. Or, maybe you want to see when people log into the system and what they're doing once they do log in. For all this and more, you have the auditd system. It's a really cool system, and I think that you'll like it.

Note

One of the beauties of auditd is that it works at the Linux kernel level, rather than at the user-mode level. This makes it much harder for attackers to subvert.

On Red Hat-type systems, auditd comes installed and enabled by default. So, you'll find it already there on your CentOS machine. On Ubuntu, it isn't already installed, so you'll have to do it yourself:

sudo apt install auditd

On Ubuntu, you can control the auditd daemon with the normal systemctl commands. So, if you need to restart auditd to read in a new configuration, you can...