Computer Viruses

Viruses, worms and Trojan horses are human-made software programs created specifically to wreak havoc on personal computers and networks. The chance of contracting one of these computer viruses over the Internet has increased dramatically. In fact, unless you run anti-virus software, your computer will almost certainly become infected. Typically, you get a virus by opening infected e-mail attachments.

Some viruses are relatively harmless to individuals. They just attach themselves to outgoing messages or e-mail themselves to all the contacts listed in your address book. The sudden flood of e-mail overwhelms mail servers, causing the system to crash.

Other viruses are more destructive and may lie dormant until a certain date. Then they spring to life to do their dirty deeds. Sometimes a strange message appears on your screen, or data and programs may be modified. In the worst case, all the files on your hard drive may be wiped out. These pernicious programs start on one computer, then replicate quickly, infecting other computers around the world.

In 1988 a student at Cornell University sent out a virus out by accident, infecting more than 6,000 computers