Chapter 11. Keeping your computer safe

Table of Contents

Change your password regularly
Don't use shared accounts
Lock your screen while away
Set up a firewall
Use common sense when working in the web
Back up on a regular basis

This is a brief guide on keeping your computer safe from security threats. We will guide you through seven different tips:

Change your password regularly

In addition to having strong passwords, it is wise to change your password regularly. To change your password, follow the steps below:

  • Open Settings ManagerUsers and Groups

  • Click on your username on the list

  • Click Change... next to the Password label

  • First enter your Current password

  • Now you can either

    • Generate a random password by selecting Generate random password and pressing Generate

    • Choose your new password yourself by typing the new password to the New password and Confirmation fields

  • Finally, click OK to confirm the password change


While it is possible to make Xubuntu log in automatically on boot within the user dialog, automatic login is highly discouraged because it provides less security for your system. Please turn on automatic login on only if you can trust everybody that has access to the computer.

Don't use shared accounts

When Xubuntu is installed, it is set up for a single person to use. If more than one person will use the computer, it is best for each person to have their own user account. To read more about adding users, refer to the section called “Users and groups”.

Lock your screen while away

Locking your screen prevents other people from accessing your computer while you are away from it. All of your applications and work remain open while the screen is locked.

To lock the screen, press Ctrl+Alt+Delete or click Lock Screen.

To unlock the screen, move the mouse or press a key. Then, type your password and either press the Enter key or click the Unlock button.

If more than one person has a user account on your computer and the screen is locked, other users can press the triangle button to the right of the user name, select their name from the list and enter their password to use the computer, even while the screen is locked. They will be unable to access your currently open work and you will be able to switch back to your locked session when they have finished using the computer.

Set up a firewall

Firewalls help to prevent security breaches by blocking connections to your computer from unknown sources. No firewall is enabled in the default Xubuntu installation. However, you have a couple of options for enabling a firewall to protect your computer against unauthorized access by people on the Internet or your network.

You can install a firewall from Ubuntu Software Center. One such option is Firestarter, which is available from the Universe repository. For help and advice on configuring Firestarter, see the Firestarter Online Manual.

More advanced users may wish to use the UFW firewall, which is installed, but not enabled, in the default Xubuntu installation. See the UFW Community Help Wiki on the Ubuntu wiki for more information.


To check that your firewall is working correctly, make use of an online firewall testing service such as ShieldsUP.

Use common sense when working in the web

Here are a few tips for keeping safe online:

  • Never reply to unsolicited mail (see more info below) or even click on the links in an email. Doing so usually results in more junk mail being sent to you.

  • Never click on links in emails which lead to websites asking for your password or other confidential information. It is possible for the text of the link to give one address when really it opens up another (possibly dangerous) address. Instead, type the link directly into your web browser yourself and proceed from there.

  • If a website asks for your financial details, ensure that it is secure. In the Firefox web browser, secure websites have a padlock icon to the left of the address. Click on the padlock to read more information about the security of the website.

  • Only download and run software from sources that you trust. By default, you can only download software directly from Xubuntu.

Unwanted (unsolicited) mail tends to fall in to one of several categories:

  • Spam (junk) email, where people offer unwanted services and products

  • Scam emails, where people pretend to ask for help in exchange for large sums of money

  • Phishing emails, where the message appears to be from a bank or other online service, asking you to enter your personal and financial details or passwords

Back up on a regular basis

A problem that you may occasionally encounter is the unexpected loss of some of your work and settings for one reason or another. The causes of such data loss are many and varied; they could be anything from a power failure to accidentally deleting a file. It is highly recommended that you make regular backup copies of your important files so that, if you do encounter a problem, you will not have lost those files.

It is wise to store backup copies of files separately from your computer; that is, you should make use of some form of file storage which is not permanently attached to your computer. Options include but are not limited to writable CDs and DVDs, external hard disks, USB disks and other computers on the network.

A simple way of backing up your files is to manually copy them to a safe location (see above) by using the File Browser as well as the Archive Manager which lets you compress files and pack them together. Alternatively, you can use a dedicated backup application.


There are numerous dedicated backup applications available in the Ubuntu Software Center, including Dejà Dup and luckyBackup.

General advice on how to keep good backups:

  • Back up on a regular basis

  • Always test your backups after you make them to ensure that they have been made correctly

  • Label your backups clearly and keep them in a safe place