Whilst the concept is not new (remember "blue pill"?) this is a different approach:

Security researchers have developed a new type of malicious rootkit software that hides itself in an obscure part of a computer's microprocessor, hidden from current antivirus products.
Called a System Management Mode (SMM) rootkit, the software runs in a protected part of a computer's memory that can be locked and rendered invisible to the operating system, but which can give attackers a picture of what's happening in a computer's memory.
The SMM rootkit comes with keylogging and communications
Story is here:


Basically it means that current anti-malware applications cannot detect them