[nl]

See this for non-classified evidence: https://news.ycombinator.com/item?id=14620389

I don't believe there are any claims Russia successfully hacked voting machines (I may have missed developments in the last week though). I believe there are claims they did successfully attack voter registration databases, but there are no real claims (except by left-wing conspiracy theory people) that they changed those databases - just stole data. I believe there is no non-classified evidence of this though (although I didn't read the document that Reality Winner sent to the Intercept, so that may document some evidence).

China has a well known hacking group (ATP-1) - see [1] for further information. There is no evidence or real claims they are involved in political interference within the US. OTOH they are quite good at industrial espionage and tracking Chinese dissidents.

I'm not very familiar with North Korea's group, but it is widely believed to be responsible for the Sony hack. I found that bizarre, but NK actions often are.

[1] https://www.fireeye.com/content/dam/fireeye-www/services/pdf...