Once you’ve installed Ubuntu with security in mind and reduced the possibility of network attacks on your system, you can start thinking about security on an application level. In the event that a malicious file is opened on your system, will an attacker be able to access every file on the computer? The chances are much slimmer if you put the proper defenses in place.
In this third part to our mini-series on strengthening your primary Ubuntu installation, you’ll learn how Ubuntu package repositories work, which repos you should avoid, and how to update. Also, you’ll see how to import additional AppArmor profiles to limit resources that apps can use, as well as create sandboxes to completely isolate unsafe applications from the operating system.