When you register for Internet access you agree to make sure that your Internet connection cannot be abused by others. All customers should therefore have installed an antivirus program and a firewall. This prevents intrusions of your computer. Use a search engine and search for free firewall and anti-virus software.


Firewalls filter traffic passing between two or more networks, often between a private network and the Internet. A firewall can also be installed as an application on a computer that should be protected.

The firewall inspects and validates received and sent network traffic using a set of rules. The firewall includes a set of rules suited for common Internet usage, the rules can also be altered by the user to allow specific applications and services.


Computer viruses are programs that spread by infecting the operating system or an application in such a way that the program is run when the operating system or application starts.
When an infected program runs it tries to spread to other computers and performs other tasks that it was designed for.


A trojan horse is a computer program that appears to be for fun or profit, but causes damage when installed by a user. It can be a program that is designed for that specific task or it may be a modified version of a current application.
Common functions of trojans are sending spam, spy on the user, collect passwords and logins or enabling the computer accessed and controlled by a remote user.


A worm is an application that spreads through vulnerabilities of computer programs. A worm can carry other malware such as a trojan. By frequently upgrading the software in your computer, you can prevent worms from infecting your computer.

Spy programs

Spy programs (Spyware) are used to spy on a computer or collect information such as passwords and logins, for example bank logins.

In order to protect yourself from infection of malware you should have an antivirus program installed on your computer.

Operating system updates

Malware often spreads through vulnerablities in your computer. By frequently upgrading the software in your computer you protect yourself from computer viruses. The procedure to upgrade the software in your computer can be found below.


Click Windows Update in Start-menu.

Mac OS X

Click Software update in Apple-menu.