Do you mean some Russians used Ukraine as a money laundering middleman, specifically through corruption of politicians and elites in the system there? Because it sounds like it. Before the "conflict" (invasion) happened.
I'll leave your imagination to judge who used ukraine as money laundering machine. To have some supplementary data for that, we can look where the money entering ukraine come from for say last 5 years. You can easily find how much was coming from russia and compare it with flow from say EU. You should be capable of drawing your own conclusions after.
