Phishing attacks that try to steal personal information could soon be a lot nastier warns a security expert.
Online bank users have been hit by phishing attacks
Sophisticated tricks that make fake messages look more plausible could mean many more people fall victim warns researcher Markus Jakobsson.
These new attacks could exploit online social networks or tune messages to an individual's circumstances, he said.
To combat these new types of attack, Mr Jakobsson recommends reducing how much personal data people share.
Phishing attacks have become more prevalent recently as net-savvy criminals find better ways to make their fake e-mail messages look legitimate.
Some of the most sophisticated phishing e-mail messages refer people to sites that look exactly the same as the website of whichever financial firm or online company they are targeting.
Coding tricks can hide the real locations of these fake sites and many people have unwittingly handed over key information such as login names, passwords and account numbers.
One recent attack overlaid the browsing bar on Microsoft's Internet Explorer browser with a fully functioning fake to hide the true origins of the site users were looking at.
But Markus Jacobsson, co-director of the Center for Applied Cybersecurity Research, at Indiana University said future attacks could be even more sophisticated and, as a result, catch even more people out.
Phishing gangs might fake network problems
"I came up with the worst kind of attacks I could think of and then worked on how to defend against them," he said.
Future phishing attacks could be "context aware" said Mr Jakobsson and take advantage of what attackers can find out about potential victims.
An example of such an attack would involve e-mails sent to people who bid on an item in an eBay auction. The e-mail could falsely claim that a person had won the auction and ask them for personal details to complete the sale.
Another such attack could mine social networks, such as Orkut, to find out who knows whom and use the names it finds to create fake e-mails that look like they come from a victim's friends or relatives.
"A phisher can find out whether a person in your 'personal network' list is a wife, a husband, a sister or a business associate, and take advantage of that," he said.
A third type of attack could fake a problem with a user's net access and then send an e-mail posing as a service firm keen to fix the problem.
Mr Jakobsson suspects that such sophisticated attacks could catch out up to 50% of people. Statistics show that a maximum of 3% of people fall victim to current phishing e-mail attacks.
While technology will help combat some of these attacks, Mr Jakobsson said action needed to be taken by users too.
"Personal information should only be displayed publicly on Web sites if it is absolutely necessary, or if a user gives his or her specific assent, knowing the risks," he said.
"Government can help by requesting or requiring these changes," said Mr Jakobsson.