5.7

Klez Worm

Klez is a computer worm that spreads through email, it first appeared late 2001, around October.
It can infect machines running Microsoft Windows. The email always has a text portion and one or more attachments.
The text portion consists of either an HTML internal frame tag which causes buggy e-mail clients to automatically execute the worm, or text that makes you want to open the attachment.
When you open the attachment, Klez will search for addresses from the victim's e-mail address books, and also searches the hard drive for addresses from the Web browser cache or temporary files.
(Pc World)

Another worm is Koobface, an anagram of Facebook, that targets users of Facebook, MySpace, Bebo, etc.
Koobface attempts to gather personal details such as credit card information.
Koobface spreads by delivering Facebook messages to people that are 'friends' of someone on Facebook whose computer has already been infected. The messages contain innocuous subject headers such as "Paris Hilton Tosses Dwarf On The Street", "LOL", "My friend catched you on hidden cam", and "My home video :)" followed by a link.
This link sends the recipient to a flash website where they have to ‘update’ this then infects there PC, sending them to more infected websites.
(Wikipedia)

The main, well heard of anti virus’ are McAfee, Norten and Kaspersky. A list shows that the top 3 Anti Virus software is “BitDefender” “Kaspersky” and “Webroot” BitDefender being the cheapest at $24.95