Cybercrime cost the global economy an estimated $445bn last year, up to a fifth of the value generated by the internet, says security firm McAfee.

Nine in ten British corporations and small businesses were affected by a cyber attack during the period, with a total cost to the economy of $11.4bn, making the UK the fifth most affected country in the G20.

Computer crime is predicted to continue to increase as businesses move online, with losses from intellectual property theft also set to rise as thieves become better at using the information they steal.

Jim Lewis of the Center for Strategic and International Studies (CSIS), which compiled the report, said: "Cybercrime is a tax on innovation and slows the pace of global innovation by reducing the rate of return to innovators and investors."

It also estimated by the report that 150,000 European jobs were affected by cybercrime in the year, as well as 200,000 from the US.

"For developed countries, cybercrime has serious implications for employment," Lewis added. "The effect of cybercrime is to shift employment away from jobs that create the most value. Even small changes in GDP can affect employment."

Researchers collated estimates of both indirect and direct costs from governments and security firms, including loss of intellectual property, financial assets, and sensitive information, as well as missed opportunity, and the costs of protecting and recovering from cyber attacks.

"It is clear that cybercrime has a real and detrimental impact on the global economy," said Raj Samani, EMEA chief technology officer at McAfee. "Over time, cybercrime has become a growth industry: the returns are great, and the risks are low.

"However this situation is not irreparable as stronger technology defences, greater collaboration between nations, and improved public private partnerships could prevent and reduce the loss from cybercrime."