Microsoft admitted today that a serious flaw in security has left all users of Internet Explorer, the default web browser for most people, vulnerable to attack from hackers.
The loophole allows criminals to commandeer victims’ computers by tricking them into visiting tainted websites that steal passwords. Computer users are advised to switch to an alternative internet browser, such as Firefox or Google Chrome, to be certain to avoid hackers who have so far corrupted an estimated 10,000 websites.
Here are the links to the Firefox and Opera web browsers. Microsoft has also has a security advisory on TechNet if you're, you know...insane enough to stick with their products...
Or for sweet heaven's sake, dump all this nonsense once and for all, and get a Mac :)
UPDATE: Microsoft issues a temporary fix.