Internet security has deteriorated markedly this year as a new generation of invasive computer attacks, often masterminded by criminal gangs, has reached a heightened level of sophistication, according to the latest studies of online threats.

"It's getting worse year after year," warned Pat Peterson, chief security researcher at Cisco Systems, who blamed the deterioration on the fact that computer "hacking" is quickly turning into big business. "Capitalism is working against us," he said.