I am not sure this would even be illegal.
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The Supreme Court has ruled on numerous occasions (New York Times v. United States, 1971 among many others: http://www.newseuminstitute.org/first-amendment-center/primers/leaks-and-the-media/) that First Amendment supersedes the Government need to block or legally punish citizens or media from collecting and publishing such data.

This is true even if the 'leaker' committed a felony crime in collecting and revealing the information.   The media need not even reveal sources under Grand Jury or Court ordered subpoena.

Of course, there are differences here, as Russia is a foreign country but the principle is the same.   I think therefore that the legal path to criminal guilt in this case would yet again involve a Supreme Court decision and would guess that First Amendment rights would again prevail over the Government position.