...heck, I'm not even 90% sure that compilers don't add backdoors to software (it's not paranoia... but with a 30 y o idea, you can imagine that people have had time to refine it to unimaginable subtlety :) http://cm.bell-labs.com/who/ken/trust.html)
What if the CIA infiltrated Intel. So the i3 - is a dual core with the 3rd core that belongs to the US, similar to i5 and i7. :-)
- can run while the CPU is off
- isn't controlled by the CPU (except some protocol which is voluntary on the ME side)
- has access to the onboard GPU's framebuffer
- has access to onboard USB and on-chipset NIC
- can access RAM, bypassing the OS (_maybe_ host-controlled, since the only known use is IDE-R)
Scary enough?
On AMD the situation looks safer for now: while they have _two_ embedded controllers with firmware, from what we (coreboot developers) could gather, their reach into the system is much more limited: they could probably DoS the system by killing access to RAM and/or turn off the fans
The kill switch could be anything:
1. Some particular frequency that causes the CPU to malfunction deliberately. Just a 1 bit malfunction is enough. 2. Something delivered via an OS update patch.
For years Microsoft has been accused of building or allowing back doors in to windows. If that is true, none of these schemes will work, right?
For years now, I have just assumed that my computer is a government spy sitting on my desk. OK, paranoid, no real proof what so ever, and OTT. But, I feel it is wise to assume and act like that is true. Or, know the risk you are taking.
How to be secure on the internet? Don't use the internet.