Several days ago it was widely reported that all version of the Internet Explorer web browser from Microsoft from version 6 to version 11 (the current version) were vulnerable to a new and serious zero day exploit. The exploit would allow an attacker to gain control of a computer and have the same rights as the currently logged-in user.
Microsoft has released a security patch to protect against this vulnerability. Users should not browse the web using Internet Explorer until they have downloaded and installed this patch. Fortunately,doing so is as easy as running Windows Update. This even applies to otherwise unsupported Windows XP computers. So get to it!