Re how this kind of thing can work: https://www.usenix.org/legacy/event/leet08/tech/full_papers/king/king_html/ https://www.usenix.org/legacy/event/leet08/tech/

Re how this kind of thing can work: https://www.usenix.org/legacy/event/leet08/tech/full_papers/king/king_html/ https://www.usenix.org/legacy/event/leet08/tech/full_papers/... "There is a substantial design space in malicious circuitry; we show that an attacker, rather than designing one specific attack, can instead design hardware to support attacks. Such flexible hardware allows powerful, general purpose attacks, while remaining surprisingly low in the amount of additional hardware. We show two such hardware designs, and implement them in a real system. Further, we show three powerful attacks using this hardware, including a login backdoor that gives an attacker complete and highlevel access to the machine. This login attack requires only 1341 additional gates: gates that can be used for other attacks as well. Malicious processors are more practical, more flexible, and harder to detect than an initial analysis would suggest."