Microsoft finds bug in Intel ME
 

There is even malware exploiting it

Microsoft's security team has come across a malware family that uses Intel's Active Management Technology (AMT) Serial-over-LAN (SOL) interface as a file transfer tool.

Intel's AMT SOL is part of Intel's ME, a separate chip inside Intel CPUs that runs its own OS and stays on even when the main CPU is off. This makes it a rather good place for malware to hit.

http://fudzilla.com/news/processors/...ug-in-intel-me