Many were caught off-guard by the worm.

Symantec has admitted that it was caught off-guard by Conficker, the computer worm which has infected several million computers across the globe since it struck around a year ago.

Speaking at a press conference to discuss the security vendor's predictions for the coming year, Symantec Security Response senior manager Orla Cox said that the firm had overestimated the preparedness of end users to deal with such a threat.

"Conficker was the big event of the year and somewhat caught us off-guard. We knew that the vulnerability had the potential to be used by malware, but we felt people had learned their lesson from the past," she said.

"We were wrong. It was really interesting to see how slow some people were to patch known vulnerabilities."

Cox also argued that the coming year could see a turning point in the evolution of rogue anti-virus software, often referred to as scareware, rogueware or ransomware.

"It may be reaching a saturation point as users become more aware of it, but on the other side we could see it go down the more malicious route," she warned.