The CIA took control of the SIM card manufacturer company through in-q-tel years before and willingly sold their shares just before the keys got stolen by NSA/GHCQ.

It was a big deal at the time known as "l'affaire gemplus" and it prompted the french government to set up the "Fonds stratégique d'investissement" or strategic investment fund, sort of a french in-q-tel.

Intel being a US company it is probable the US agencies have their ways with them.

I wouldn't be surprised if the NSA worked with Intel to design their microcode update mechanism (selecting algorithms with advisements against classified breaches; generating key material and sharing between themselves; etc.) That would serve the NSA's interests in both their SIGINT and COMSEC roles at once.