Why is it always Russia?
This is into "not even wrong" territory. Brazil has a fairly close relationship with Russia, they're a fellow founding BRICS member - and Lula was president when it was formed. What would Putin get from having US (Trump) ally Bolsonaro Jr. over him?
And while it's great that the murder-happy fascist didn't win, it's not exactly a great win for democracy. It's just stopping the bleeding. Besides the obvious problem of being allied with Russia and China, Brazil has a worrying "anti fake news" law. Like elsewhere, it seems the slightly-better guys aren't eager to roll back power grabs that now benefit themselves.
If we look at fascists taking power in south america, then the us is an better suspect, since they already did this before.