The ILOVEYOU virus in 2000 had a similarly devastating effect. In January 2007, a worm called Storm appeared — by October, experts believed up to 50 million computers were infected. That’s pretty impressive when you consider that many viruses are incredibly simple. When you listen to the news, you hear about many different forms of electronic infection. The most common are:
A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
An e-mail virus travels as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim’s e-mail address book. Some e-mail viruses don’t even require a double-click — they launch when you view the infected message in the preview pane of your e-mail software [source: Johnson].