Virus Definitions

There are several different types of viruses:

Viruses

A virus is a manmade program or piece of code that causes an unexpected, usually negative, event. Viruses are often disguised games or images with clever marketing titles such as "I love you”, “Me, nude.", “Congratulations” or “Get slim now” etc. Viruses can also replicate themselves.

Trojans

A Trojan horse program is a malicious program that pretends to be a benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive. Many people use the term to refer only to non-replicating malicious programs, thus making a distinction between Trojans and viruses.

Worms

Computer Worms are viruses that reside in the active memory of a computer and duplicate themselves. They may send copies of themselves to other computers, such as through email or Internet Relay Chat (IRC).

Hoax

Hoaxes are not viruses, but are usually deliberate or unintentional e-messages warning people about a virus or other malicious software program. Some hoaxes cause as much trouble as viruses by causing massive amounts of unnecessary e-mail.

Most hoaxes contain one or more of the following characteristics:

  • Warnings about alleged new viruses and its damaging consequences
  • Demands the reader forward the warning to as many people as possible
  • Pseudo-technical "information" describing the virus
  • Bogus comments from officials: FBI, software companies, news agencies, etc.

(Information from http://us.mcafee.com/virusInfo/default.asp and http://us.mcafee.com/virusInfo/default.asp?id=glossary )