Experts at SophosLabs, Sophos's global network of virus, spyware and spam analysis centres, are warning of a phishing onslaught facing PC users, with more than one fifth now receiving five or more every day.
A web poll of more than 600 business PC users, conducted by Sophos, found that 58% receive at least one phishing email every day, while an alarming 22% receive more than five a day - evidence that the drive towards financially motivated computer crime continues to accelerate.
Recent statistics from the Anti-Phishing Working Group (APWG), of which Sophos is a member, supports this evidence, revealing that the organisation detected 15,244 unique phishing reports in December 2005, up from 8,829 in December 2004.
"The reason phishing emails are now so prevalent is due to their success rate - every day new users fall victim to these underhand and illegal tactics," said Carole Theriault, senior security consultant at Sophos.
"If you receive more than five phishes per day, you're either alert to the dangers or you're likely to have been robbed blind. With crooks employing more and more devious methods to dupe users, the best advice is to always be wary of unsolicited emails, and at all costs avoid parting with confidential information."
The dangers of phishing were highlighted once again last week when Visa Asia Pacific announced that it had uncovered and shut down 20 spoof websites to prevent cardholders from falling victim to online data theft.
The action was taken following reports that customers had received suspicious emails from the company's payments network, and Visa was quick to state that the company would never initiate contact with customers in this manner.
Although most phishes purport to be from online businesses such as Ebay, Sophos has seen a variety of different organisations being targeted, including major banks and charities.
"While organisations have a responsibility to ensure the security of their own websites, they have little control over phishers that exploit their brand behind their backs," said David Jevans, chairman of the APWG.
"Phishing attacks are likely to become even more targeted in the future, and it will therefore be all the more important for users to display caution. If in doubt, they should contact the relevant organisation to check an email's authenticity."