if you dont trust it, finish up backing everything you need and settings etc, then disconnect internet, install, run and get the key info you want. rebuild after formatting. simple!
even it wanted to, it couldnt transmit any data back.
note: the post above is my opinion. as such, when reading any recommendations from me, please do you research and seek out other recommendations and make up your own mind on your next course of action. i mean, most reasonable adults should know that, but it seems this should be stated anyways.