Yes, in my research, China and Iran came up often.
However, China and Russia were not necessarily disseminating the same information and did not necessarily have the same objectives. With Russia, we saw a tendency to favour the Republican Party, while China tended to favour the Democratic Party a little more. Each of those countries favoured the party that was most likely to be sympathetic to its government and create partnerships or sign agreements with it. Russia believed that the Democratic establishment was very anti-Russia, while China believed that it was a bit more sympathetic to its cause than the Republican Party.
Russia, China and Iran do engage in state disinformation, so those countries have organizations that are funded and sponsored by the state. They are permanent organizations whose main objective is to spread disinformation. They work at it full-time, while pursuing other objectives at the same time, obviously.