Microsoft is warning its users about a dangerous flaw in the way that Windows handles certain MHTML operations, which could allow an attacker to run code on vulnerable machines. The bug affects all of the current versions of Windows, from XP up through Windows 7 and WindowsServer 2008.
Microsoft issued an advisory about the MHTML vulnerability, which has been discussed among security researchers in recent days. There is some exploit code available for the bug, as well. In addition to the advisory, Microsoft has released a FixIt tool, which helps mitigate attacks against the vulnerability in Windows.
Following the advisory advice, fix is to simply disable MHTML for now, MS have released a tool available HERE!