Comment by PrimaryAlibi

How would it be done externally? Is it done same way as flashing the boot rom? You just need to know where the chip is for the other components? No 0-days needed? Or do you need a 0-day to do this? Is that why you think only foreign intelligence agencies are the ones who can do this? Also assume that the bios is password protected and it's configured in bios to not boot from a USB drive.