A few days ago, computer scientists revealed a wide-spread security exploit called FREAK. At first it was thought to be a vulnerability confined to Android devices and Macs, but it turns out that it affects Windows machines too.
Essentially FREAK makes use of the United States 90's government policies—which called for the inclusion of weak encryption on exported products—to launch dangerous attacks on web browsers from secure sites like .gov websites and even banks.
In an advisory, Microsoft said that the exploit affects all supported versions of Windows, and that it's currently working on a fix that will come in the form of a monthly release or an out-of-cycle updated.
You can read more about FREAK below.