Once intelligence agencies start backdooring microcode (especially in a way that chip manufacturers can't detect), I'm throwing out my computer and living in the woods.
I'm not even sure that the open source RISC-V initiative might prevent this, as theoretically the NSA could gain access to the manufacturing plant and insert their own core.
The only way to catch that at that point would be to X-ray the chip and look for their mod, or something. Anyway, assume the NSA has access to your shit, focus on preventing the random from grabbing your bank account access and stealing your money.