Microsoft is aware of active attacks using at least one fraudulent digital certificate issued by DigiNotar. A fraudulent certificate could be used to spoof content, perform phishing attacks, or perform man-in-the-middle attacks against all Web browser users including users of Internet Explorer. This issue affects all supported releases of Microsoft Windows.
Typically no action is required of customers to install this update for supported releases of Microsoft Windows, because most customers have automatic updating enabled and this update will be downloaded and installed automatically.
For more information, including how to manually install this update, see Microsoft Security Advisory (2607712) at http://www.microsoft.com/technet/security/advisory/2607712.mspx.
