The Merry Christmas virus is an email worm that started to emerge before Christmas of 2004. The worm spread via electronic mail as a small, executable file with a variety of names and extensions. The worm propagated by copying itself onto local and networked drives, as well as emailing itself as an attachment to any addresses it could harvest from the address book and files stored on the infected machine.

The Invitation virus hoax involved an e-mail spam in 2006 that advised computer users to delete an email, with any type of attachment that stated “invitation” because it was a computer virus. This is also known as the Olympic Torch virus hoax.

A virus hoax is a false report about a non-existent virus intended to cause fear and panic, in an attempt to persuade recipients to forward the warning to friends and family. Hoax messages often falsely describe an extremely dangerous virus and attempt to make their claims convincing and more dramatic by using pseudo-technical language or referencing bogus reports by well-known companies.

Today, Trojans are notorious for implementing backdoor programs that allow attackers unauthorized access to victims’ systems. Unlike traditional computer viruses and other types of malware, they are designed with the intention of exploiting infected systems, rather than replicating themselves or disabling a system completely.

The Life is Beautiful hoax virus warns of an infected PowerPoint presentation. It has been reported in Spanish, Portuguese, English, German, French and Yugoslavian. This hoax warns of a deceptively titled message carrying an infected Microsoft PowerPoint file named “Life is Beautiful.” It originally circulated in Portuguese but was later translated into English and a host of other languages.

At its height, ILOVEYOU infected 10 percent of computers connected to the Internet, causing $5.5 billion in damage. The virus’s rapid proliferation is a result of its use of mailing lists, social engineering and VBScripts. Because the viruses generated targets based on the mailing lists stored on a victim’s machine, infected messages appeared to come from an acquaintance and were often considered safe as a result.