Hoping to deal with a growing problem, Twitter has quietly introduced a feature to prevent users from posting links to malicious Web sites. But security experts say that it can be easily circumvented.

The feature was first noticed Monday by Mikko Hypponen, chief research officer with security company F-Secure. When someone tries to post a link to a malicious Web site, Twitter pops up a short notification saying "Oops! Your tweet contained a URL to a known malware site," and, after a few seconds, deletes the post.

F-Secure says it's recommended that Twitter start doing this because the site "is increasingly targeted by worms, spam and account hijacking," according to Hypponen's blog post. A month ago, technology entrepreneur Guy Kawasaki's account was misused to post a link to a malicious Web site. In recent weeks users have been hit with links to fake, and sometimes malicious, "rogue" security software.

More: http://pcworld.com/article/169519/