"This was blatantly illegal! "Jared Kushner and Russia’s ambassador to Washington discussed the possibility of setting up a secret and secure communications channel between Trump’s transition team and the Kremlin, using Russian diplomatic facilities in an apparent move to shield their pre-inauguration discussions from monitoring, according to U.S. officials briefed on intelligence reports.
Ambassador Sergei Kislyak reported to his superiors in Moscow that Kushner, then President-elect Trump’s son-in-law and confidant, made the proposal during a meeting on Dec. 1 or 2 at Trump Tower, according to intercepts of Russian communications that were reviewed by U.S. officials. Kislyak said Kushner suggested using Russian diplomatic facilities in the United States for the communications.
The meeting also was attended by Michael Flynn, Trump’s first national security adviser.
The White House disclosed the fact of the meeting only in March, playing down its significance. But people familiar with the matter say the FBI now considers the encounter, as well as another meeting Kushner had with a Russian banker, to be of investigative interest.
Kislyak reportedly was taken aback by the suggestion of allowing an American to use Russian communications gear at its embassy or consulate — a proposal that would have carried security risks for Moscow as well as the Trump team."
18 U.S. Code § 953 - Private correspondence with foreign governments
Russian ambassador told Moscow that Kushner wanted secret communications channel with Kremlin - The Washington Post