Online fraudsters are targeting wealthy web users, and the number of adults that have received phishing e-mails has nearly doubled since 2004, according to research by Gartner in the US.
The study put financial losses stemming from phishing attacks at more than $2.8bn (£1.51bn) so far in 2006.
"The good news is that this year fewer people think they lost money to phishers, but when they did lose, they lost more," said Gartner analyst Avivah Litan.
"The average loss per victim nearly quintupled between 2005 and 2006, and the thieves seem to be targeting higher income earners, who are also more likely to transact on the internet," Litan said.
According to the survey, around 109 million US adults have received phishing e-mails, up from 57 million in 2004. The average loss per victim has grown from $257 (£138) to $1,244 (£672) per victim in 2006.
The average amount consumers recovered from phishing attacks in 2005 was 80%, but in 2006 that dropped to 54%. Gartner said high income adults earning more than $100,000 a year were attacked more than other internet users.
High earners received an average of 112 phishing e-mails in the past year compared with 74 e-mails per consumer across all income brackets. The high income adults lost an average of $4,362, almost four times as much as other victims.
Phishing e-mails are impersonating banks less than before, and other brands, such as PayPal and eBay, more often.
As a result, said Gartner, banks and credit card company refunds to phishing victims were declining as a percentage of total refunds, while refunds from non-financial services companies and retailers were growing.
The Gartner survey was based on 5,000 responses from US adults online.
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