In the world there are over 400 millions of the existing viruses. More than 1/3 of computers are infected. There are many types of viruses. The worst are those stealing your credit card number and blocking the access to your photos folder on your PC. It is extremely important to have updated antivirus and scanning your computer regularly.
Yet, despite having even the best antivirus protection there is still a realistic risk of virus infection. Be aware of free movies websites, suspicious e-mails and many other unknown sources.