After reading this article, I am really curious as to how, exactly processor microcode updates from Intel or AMD are issued. In what way is the data transmitted? Is it possibly to 'firewall' these updates if one was paranoid about Putin switching to typewriters to avoid inherent computer security flaws? If I am using Linux, is it possible I am safe because I am not receiving Windows updates? I would think that someone would notice a connection from their computer to intel or an attackers server, at some point.
From what I have read, the consensus around the security community is that these attacks are not very feasible. But I am still curious as to how these updates are issued, and what type of transmission protocol is used. In order for this to be possible, the computer would have to request the connection to get through a properly configured firewall, regardless of whether the backdoor exists purely in the processor itself, and not the operating system.
Is it possible to block these updates altogether, if one was very paranoid?