How many times do I have to tell you? Get a firewall, block all inbound and outbound traffic, unplug your ethernet cable and shut off your computer. It's that easy to protect yourself.

2004 has also seen the launch of a series of threats specifically targeting wireless devices. Cabir, the first virus for mobile phones appeared in June - a proof-of-concept virus produced by the virus-writing group 29A, although it was later reported in the field in the Far East. This was followed by the Duts virus in July, another creation of 29A, and the Trojan Brador in August, both aimed at Pocket PC.

2004 also saw large numbers of Trojan droppers and Trojan downloaders. Both have one goal: to install an additional piece of malware on the victim machine, whether it's a virus, a worm or another Trojan. They simply use different methods to achieve their goal.