Steve Bannon made a statement in Micheal Wolff's recent book called, "Fire and Fury: Inside the Trump White House." Everything he said was speculative. Bannon quoted, "this is all about money laundering." The topic at hand was whether or not the Russians had a hand in making sure that Trump won the election through shady dealings.
The laundering supposedly allowed them to turn 'bad' money into 'good' money. The former White House chief strategist stated that the 2016 meeting between Trump Jr. and a group of Russians was treasonous. Bannon's remarks serve the Mueller investigation in a way that puts Trump's presidency in danger.
Steve Bannon has said that the Trump-Russia probe was about money laundering. Money laundering is when someone gets money illegally and does not admit where the money came from. Steve Bannon was the White House Chief Strategist. He worked for the Trump administration for seven months and then he was let go from his position and then showed his opposition to the Trump administration and the Republican Party.
Recently, he and Breitbart wrote and published a book about Bannon’s experience during the Trump administration in January 2018. As far as whether the Trump-Russia probe was about money laundering is difficult to say at this point since the investigation is still ongoing and the facts about each side have not been made known explicitly and in full to the general public.