The backdoors the NSA uses are known vulnerabilities, 0days, USB drops, all the normal hacker tools… and if it’s a target of sensitive enough in nature, maybe a warrant requiring Apple Update/Windows Update/whoever or whatever device needs spied on, to deliver a payload to that specific machine.
There are 3 leaks in circulation:
4.3 gigs, src only
17 gigs, src + partial assets
1 TB, src + full assets
I purchased 3/5 books of the series. The 2 free books add up to 13 hours.