Unpatched Microsoft browser hole a gold mine for hackers

IDG News Service - A long-ignored security hole in Microsoft Corp.'s Internet Explorer is proving to be a gold mine for hackers, providing an easy way for them to plant malicious programs on vulnerable machines through hacker Web sites and instant messaging applications, security experts warn.
New attacks using the vulnerability include a worm that spreads through America Online Inc.'s AOL Instant Messenger (AIM) and a malicious Web site that silently loads snooping software on victims' machines, according to independent security expert Richard Smith.
Microsoft didn't immediately respond to requests for comment.
The security hole, known as the "Object Data vulnerability," is in software code used by Internet Explorer to process HTML pages containing an element called the Object Data tag. When properly exploited, the vulnerability enables an attacker to place a malicious computer program on a user's machine. No user actions are required to infect a machine, aside from opening an e-mail message or visiting a Web page rigged by an attacker.
Microsoft issued a software patch, MS03-032, on Aug. 20 that was supposed to fix the problem. However, that patch failed to close the hole on Windows machines running Internet Explorer Versions 5.01, 5.5 or 6.0.
On Sept. 8, Microsoft acknowledged problems with the MS03-032 patch and promised to issue a fix as soon as possible. Since that time, no changes have been made to the MS03-032 patch. In the succeeding weeks, hackers moved quickly to take advantage of the company's slow response.
Recent exploits of the Object Data vulnerability include a virus that spreads over the AIM network, stealing users' account names and passwords, then mailing links to a malicious hacker Web site to the victim's AIM correspondents (or "buddy list"), Smith said.
Although the Web site associated with that threat has been removed, users who received and clicked on an infected instant message could have had their AIM accounts hijacked, Smith said.
The vulnerability also cropped up in an e-mail message containing HTML code that exploits the vulnerability. When opened, the message installs a file called "surferbar.dll" onto the victim's computer with links to pornographic Web sites, according to Secunia Ltd., a security company in Copenhagen (see story).
Although some of the new attacks are targeting holes in the MS3-032 patch, others may just be targeting users who haven't applied the patch at all, Smith said. Short of issuing an updated patch to close the hole, Microsoft should at least update its bulletin with a widely known work-around that closes the security hole, Smith said.
That fix, developed by a researcher at eEye Digital Security in Aliso Viejo, Calif., requires a small change to the Windows configuration that doesn't appear to affect any Windows features but would protect users from attack, he said.
In the meantime, hackers will continue to take advantage of the Object Data vulnerability, which is easy to exploit and powerful, he said. "The sky's the limit of what you can do with [the Object Data vulnerability]," Smith said. "This exploit is going to be used for years."

Reprinted with permission from

IDG.net
Story copyright 2009 International Data Group. All rights reserved.