It is hard to believe that some ambitious reporter with mobility could not find out who this person is. Not to mention some low-level intelligence officer.
Examine new Swiss bank accounts, etc.
I think the WashingtonComPost made it up, had it published and is using it as a basis for trashing Trump, anonymously, of course.
Without a named author, named sources collaborating the story, this is just fake news.
Anybody could make this sh*t up. Try one of the night janitors at the WashingtonComPost. They're probably making some extra money on the side.