There are a few basic steps to maintaining a secure Ubuntu system:
- Don't use root - The default Ubuntu installation does not assign a root password and you cannot log in as root. Instead, the default user account can use Sudo to run commands as root. Additional user accounts cannot even run Sudo unless they are given explicit permission. Restricting root access limits your ability to accidentally (or intentionally) screw up the entire operating system.
- Limit network services -