(via “Flame” malware was signed by rogue Microsoft certificate | Ars Technica)
Microsoft released an emergency Windows update on Sunday after revealing that one of its trusted digital signatures was being abused to certify the validity of the Flame malware that has infected computers in Iran and other Middle Eastern Countries.
The compromise exploited weaknesses in Terminal Server, a service many enterprises use to provide remote access to end-user computers. By targeting an undisclosed encryption algorithm Microsoft used to issue licenses for the service, attackers were able to create rogue intermediate certificate authorities that contained the imprimatur of Microsoft’s own root authority certificate—an extremely sensitive cryptographic seal. Rogue intermediate certificate authorities that contained the stamp were then able to trick administrators and end users into trusting various Flame components by falsely certifying they were produced by Microsoft…

