McAfee has released research that notes "a dramatic increase in online and computer-based identity theft".

The number of keylogging applications (malicious software code that tracks typing activity to capture passwords and other private information) increased by 250 percent between January 2004 and May 2006, the company said. Phishing attacks climbed 100-fold in the same period.

"Identity theft is a global phenomenon that threatens all of us, which means we all need to become more aware, more vigilant and less trusting to protect ourselves," said Jeff Green, senior vice-president of McAfee Avert Labs.

In the UK, the Home Office has calculated the cost of identity theft to the British economy at $3.2bn during the past three years. According to the Federal Trade Commission, the annual cost for consumers and businesses in the US alone reaches $50bn annually.

The McAfee Avert Labs White Paper concludes with practical guidelines for preventing identity theft and minimizing the risks of being victimised.

It advises users to beware of fraudulent emails and sites that impersonate legitimate businesses and try to trick your personal information out of you. One way is to avoid manually clicking links sent in emails, it suggests.

Strong passwords, wariness when opening attachments, and internet security software are all advised by the firm.