The year 2003 has clearly been the worst in virus history and exceeded previous years in terms of both the number of virus outbreaks as well as their extensiveness and severity.
At the same time, the entire computer virus phenomenon saw its 20th birthday this year. New trends in 2003 were primarily the way spammers began to use viruses as a tool and how several critical infrastructure systems suffered from the consequences of virus outbreaks. The network worm problems encountered during the year have shown how important it is to equip every single computer with a personal firewall. The number of known viruses is at the moment some 90,000.
When we look at the year as a whole, five cases were in a league of their own: Slammer, Bugbear.B, Blaster, Sobig.F and Swen.
The wrap-up with full details can be read at: http://www.f-secure.com/2003/

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