Viruses are everywhere.
They have become extremely difficult, if not impossible to avoid. If you haven't had a run-in with one yet, you are in the minority. Big companies are spending big money to protect their assets and their data. A prevailing myth about viruses is that they can be avoided by staying off the Internet, but one network manager reports that he encountered a virus on a new computer that he tested right out of the box. He explains that the virus must have been present on a disk that was used in setup or testing at the factory.