There were almost 1,500 unique phishing attacks in June, a monthly increase of 19 percent, according to a report published by the Anti-Phishing Working Group (APWG) on Wednesday.
Most phishing attacks are emails pretending to come from banks or financial institutions. They usually ask the recipient to "confirm" their personal details after clicking on a hyperlink. The link directs the victim to a fake or doctored Web site that is often indistinguishable from the original and is designed to collect information that can be used for fraud and identity theft.
Jack Clark, technology consultant at antivirus firm McAfee, said the number of phishing attacks is expected to keep growing because more people are using the Internet and the phishers have started making money from the scam.
"New people join the Internet every day and more people are putting their trust into online transactions. The larger the market gets, the more opportunity there is for criminals," said Clark.
Clark said that phishing is far from a new crime, it is actually a very old scam that has been adapted for cyberspace.
"This isn't new. You hear sad stories about old grannies being conned on their doorsteps. This is exactly the same but for the online world," said Clark.
Internet filtering company Websense, which helps the APWG analyse its results, found that a quarter of phishing Web sites are hosted in the US and most are only online for just over two days.
Election fever in the US led some phishers to spoof Democratic candidate John Kerry's Web site and steal campaign contributors' credit card details.
Susan Larson, vice president of global content at email security firm SurfControl, said that although the Web sites have been taken down, there will be more.
"Phishers and other scam artists are masters of leveraging timely events to exploit the unwary. People excited by a new candidate are more likely to volunteer confidential information like email addresses and credit card numbers," said Larson.
In July, Barclaycard issued 5,000 of its UK customers with credit and debit card readers that were specially designed to help prevent fraud and reduce exposure to phishing attacks.