A higher than expected percentage of internet users are falling victim to phishing scams, US academics claimed today.

Researchers at Indiana University's School of Informatics said that phishers targeting US adults could be netting responses from as much as 14 per cent of the targeted users per attack.

The university's study simulated phishing tactics used to elicit online information from eBay customers.

The online auction giant was selected because of its millions of users, and because it is one of the most popular targets of phishing scams.

The researchers noted that recent surveys by the Gartner Group suggest that about three per cent of adult Americans are successfully targeted by phishing attacks each year.

But this amount might be conservative given that many users are reluctant to admit falling for such a scam, or may even be unaware of it.

Other surveys may have resulted in overestimates of the risks because of a misunderstanding of what constitutes identity theft.

"Our goal was to determine the success rates of different types of phishing attacks, not just the types used today but those that have not yet occurred in the wild," said Markus Jakobsson, associate professor at the IU School of Informatics.

Jakobsson is also an associate director of the IU Center for Applied Cybersecurity Research, which studies and develops countermeasures to Internet fraud.