Microsoft releases Security Advisory 2718704

We recently became aware of a complex piece of targeted malware known as "Flame" and immediately began examining the issue. As many reports assert, Flame has been used in highly sophisticated and targeted attacks and, as a result, the vast majority of customers are not at risk. Additionally, most antivirus products will detect and remove this malware. That said, our investigation has discovered some techniques used by this malware that could also be leveraged by less sophisticated attackers to launch more widespread attacks. Therefore, to help protect both targeted customers and those that may be at risk in the future, we are sharing our discoveries and taking steps to mitigate the risk to customers.

As part of the phased mitigation strategy we outlined on the MSRC blog, an update was released with Security Advisory 2718704 that prevents unauthorized certificates from being used to attack Windows systems. In an effort to provide additional protection for customers, the next action in our mitigation strategy is to further harden Windows Update as a defense-in-depth precaution. Now that we have seen broad adoption of Security Advisory 2718704, our deployment of the security hardening update to Windows Update and Windows Server Update Services (WSUS) infrastructures will begin to roll out over the next few days.