tsu doh nimh writes "Google and Microsoft today began warning users about active phishing attacks against Google's online properties. The two companies said the attacks resulted from a fraudulent digital certificate that was mistakenly issued by a domain registrar run by TURKTRUST Inc., a Turkish domain registrar. Google said that on Dec. 24, 2012, its Chrome Web browser detected and blocked an unauthorized digital certificate for the '.google.com' domain. 'TURKTRUST told us that based on our information, they discovered that in August 2011 they had mistakenly issued two intermediate CA certificates to organizations that should have instead received regular SSL certificates,' Google said in a blog post today. Microsoft issued an advisory saying it is aware of active attacks using one of the fraudulent digital certificates issued by TURKTRUST, and that the fraudulent certificate could be used to spoof content, perform phishing attacks, or perform man-in-the-middle attacks against virtually any domain. The incident harkens back to another similar compromise that happened around the same time-frame. In September 2011, Dutch certificate authority Diginotar learned that a security breach at the firm had resulted in the fraudulent issuing of certificates."