Oh I forgot, its on the internet therefore must be true....
BTW you can't infect the firmware on a drive without running an executable on the machine it is attached to...
But don't worry, "its just physics".
Take a read at the article linked. If this really is the NSA (and a lot of evidence points to it) they have a nearly unlimited budget. The stuff that equation group has managed to pull off is truly mind blowing. Chaining multiple attacks together and even breaching air gaps. These guys know what they're doing. I wouldn't doubt they could gain root privilege, run kernel level code, rewrite hard drive firmware, and control the entire booting process and handling from there on out completely silently.
The only thing is I'm most likely not worth their time, and it looks like they're actively trying to limit their attacks to their specific targets.