Way back in 1949, theories for self replicating programs were first developed. In 1981, Apple Viruses 1, 2, and 3 were some of the first viruses found “in the wild.” In 1983, Fred Cohen formally defined a computer virus as “a computer program that can affect other computer programs by modifying them in such a way as to include a (possibly evolved) copy of itself.” In 2004, the MyDoom virus ran up a bill of $250 million in lost productivity and tech support expenses.

For a comprehensive history of the Computer Virus Timeline you can visit http://www.infopleasel.com/ipa/A0872842.html, but suffice it to say that in 2006, computer viruses and anti-virus protection are just a way of computer life. Viruses today are often used to steal confidential information and most everyone who keeps data on their computers has anti-virus software.

Now in addition to viruses we have spyware, Trojans, worms, adware, dialers, and more. Most anti-virus software protects your computer from viruses, worms, and trojans, but not all of them protect against spyware. According to Microsoft

“You might have spyware or other unwanted software on your computer if:
• You see pop-up advertisements even when you're not on the Web.
• The page your Web browser first opens to (your home page) or
your browser search settings have changed without your knowledge.
• You notice a new toolbar in your browser that you didn't want, and
find it difficult to get rid of.
• Your computer takes longer than usual to complete certain tasks.
• You experience a sudden rise in computer crashes.”