From Politico:
Obviously, we know most of the people from his entourage,” Russian Deputy Foreign Minister Sergei Ryabkov told the state-run Interfax news agency in an interview reported on by The Washington Post. “Those people have always been in the limelight in the United States and have occupied high-ranking positions. I cannot say that all of them but quite a few have been staying in touch with Russian representatives.”
True to form, Trump lied about this during the campaign:
The Manhattan billionaire has repeatedly denied any connection to the Russian government, claims that appear to be contradicted by Ryabkov.