Completely reinstall everything on the Mac Let's say that I am paranoid and I want not only to wipe and reinstall OS X, but also recovery, SMC, firmware and everything in the Mac hardware that could have been infected with malware. Is there any way to accomplish this?
You could get a brand new SSD disk and install OS X on it, carefully clean wipe the current one.

In addition you could get EFI and SMC firmware from Apple.

https://support.apple.com/en-gb/HT1557

https://support.apple.com/en-us/HT201518

The before you do anything (since the malware could creep right in again) install something like LittleSnich and block everything from to Network and only allow fully trusted stuff.