Black Hat In-Depth A design flaw in Intel's processors can be exploited to install malware beneath operating systems and antivirus – making it tough to detect and remove. It allows smart hackers to run rootkit code at the very lowest level on the computer, out of reach of the operating system, its applications, and even the hypervisor. This means the rootkit can, among other things, silently monitor and record the user's every keypress, mouse click, and download.
http://www.theregister.co.uk/2015/08/11/memory_hole_roots_intel_processors/
Yep read this, nasty stuff.