'Code Red ate my bonus!'

Computer viruses have cost companies a total of $10.7bn so far this year in lost revenues and the cost of repairing infected systems.

A study by research company Computer Economics says Code Red was one of the costliest viruses - accounting for $2.6bn. But Code Red is still well down on the costliest virus of all time - the Love Bug. Last year computer networks worldwide were hit by the bug, which wreaked havoc worth staggering $8.7bn.

Michael Erbschloe, vice-president of research at Computer Economics, told Reuters: "If there are no new bugs, we will land under $15bn. But one more big outbreak that becomes a billion dollar bug would put the total over last years."

This year's other big viruses included SirCam which infected more than 2.3 million computers worldwide causing damage worth $1.03bn, according to the research.

The total cost of damage is calculated on the basis of loss in productivity and the clean-up process afterwards. The loss of productivity includes downtime suffered by users as well as company IT staff dealing with the virus during and after the attack. The clean-up process includes patching systems and time and money it takes for a company to return back to normal operations.