A security vulnerability in Microsofts Internet Explorer 9 and Internet Explorer 10 browsers has left millions of PC users open to infection from a handful of compromised websites. This method, if not the malware, is similar to the current Adobe Flash Player zero-day exploit attack campaign on visitors to certain foreign-policy websites. In the case of the Microsoft vulnerability, malefactors took advantage of the flaw before developers could address it, and snuck malware onto certain websites without site administrators knowledge.