What are computer viruses, worms, and Trojan horses?
A computer virus, according to Webster’s Collegiate Dictionary, is “a computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data)”. Two categories of viruses, macro viruses and worms, are especially common today. Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread is not directly under human control. One example of a virus is the Anna Kournikova virus, which comes in the form of a picture sent through e-mail.
