They probably are. I used to write software for a financial institution and we saw a lot of traffic from Chinese and Russian IP's hitting our firewalls constantly (ssh login attempts with typical default passwords, random wordpress exploits, that sorta thing). It wasn't very sophisticated so I don't think it was state sponsored or anything, probably just random cyber criminals trying to hit US targets because their governments wouldn't care.
Do they really need to bother? Plenty to steal in cryptoland, and it's much much easier.