If you are a website owner, the one thing that can give you nightmares is any malware or virus infecting your site. Your website is probably hosted on an internet service provider's web hosting servers. And you don’t know if there are enough anti-virus measures that have been installed to protect customers' web sites against malicious attacks.
The computer and internet community knows the menace caused by hackers, malware and virus spreaders. They don't spare any website and try to enter and destroy websites at will. They have caused damage amounting to millions on various websites, and some of the viruses have gained notoriety like Chernobyl, I LOVE YOU, Code Red, etc.
A virus can attack your computer, your mobile phone and any other device that's hooked to the internet. Some viruses cause a mild irritation and can be cleaned up easily. On the other hand, some of the viruses are so vicious that they can wreck the computer. That’s why any device that uses the internet needs to be protected against virus attacks. Also, remember that even a USB on which your friend or colleague has copied a video or work item for you could contain a virus which will infect your computer.