T9000 is a newer variant of the T5000 malware family, also known as Plat1.
The malware goes to great lengths to identify a total of 24 potential security products that may be running on a system and customizes its installation mechanism to specifically evade those that are installed. It uses a multi-stage installation process with specific checks at each point to identify if it is undergoing analysis by a security researcher.
Read lots more here but it may be too technical for many.
Bottom line: Don't open any attachments you weren't expecting, and use caution even if you were expecting something...