I will say just because the Russians are not publicly complaining that they are being hacked means they are not getting hacked. Why would the CIA, NSA, other western spooks, their proxies, or even rogue actors in the west not hack the Russians? That is the job of the CIA. That is what the CIA had been doing from its inception. Hacking is just carrying spycraft into cyberspace.
My suspicion is that it is more than a case of perhaps. If "hacking" basically is gaining unauthorised access to data in a system I do not see why that is not the CIA, NSA main job. That is their job. If they are not engaged big time in hacking then methinks someone is wasting gomint money. So I expect US Intelligence Services to be excellent hackers. I suspect they are good at hacking and hack a lot. How else do they track terrorists on whom they occassionally rain missiles from drones?