I do not know. Haven't bothered to search for the source either. Figured it would be taken as a theory, not authoritative or proof.
FBI: Lisa Page Dimes Out Top FBI Officials During Classified House Testimony
Bureau Bosses Covered Up Evidence China Hacked Hillary's Top Secret Emails
Truepundit - July 17, 2018
I really wish everyone would quit using the term “hacked server”.
It isn’t hacked if you are given access. And No, I don’t think I am picking nits.