We know for certain that John Podesta did.
http://www.americanthinker.com/blog/2017/03/john_podesta_in_bed_with_the_russians_all_along.html
https://www.wsj.com/articles/john-podesta-and-the-russians-1477262565
I did a whole long blog post on Hillary Clinton’s ties to Russia that should be considered in a full investigation of the Russia role in the campaign. If Trump had these same connections, it would be code nuclear hysteria:
http://dtforpres.blogspot.com/2016/09/hillary-clinton-and-democrats-have.html