Comey didn’t say anything!!!
This was Brennan saying Comey said. Brennan is not to be trusted.
He may have talked to Comey and asked “do you think the Russians are capable of hacking US cyber infrastructure?”. And Comey may have answered “Yes”. Then Brennan reports Comey agrees that Russians hacked something and caused Clinton to lose, etc.
Until there is a press statement by Comey himself, this is not to be believed.