A newly discovered vulnerability in Microsoft's Internet Explorer browser could be a powerful new tool for scammers, allowing them to convincingly mask the real origin of Web pages used to trick targets into revealing sensitive information.Attackers could use a specially crafted URL to display a different domain name in the address bar than the Web page's actual location. This practice is known as "spoofing."

Spoofing is a favorite tactic of spammers hoping to con users out of passwords and other personal details with e-mails pretending to be from banks, e-commerce sites, software vendors, and other trusted institutions.

The vulnerability afflicts several versions of Internet Explorer, including a fully patched edition of the software's latest release. Several other popular browsers, including Mozilla and Opera, are not affected and correctly display the actual location of sites taking advantage of the URL hack. Microsoft says it is investigating reports of the vulnerability. When that inquiry is complete, the company will take whatever steps it deems necessary, such as issuing a new patch, a spokesperson says.