Boris was a foreign exchange intern working for Galaxy News Network. Believed to smell (which was actually an old lunch stuffed into a desk of a permanent employee as a practical joke that went bad quickly), he was commonly the subject of prejudice and harassment from at least one other employee of the GNR. Despite that, Boris was quite humble and grateful for the opportunity to live in the United States on an exchange program as an intern. He deliberately used a heavy accent when speaking English, which was apparently interpreted by U.S. folks as a sign of intelligence. He had an excellent grasp of English, in fact, and used it to apologize to Jim (the employee who harassed him) for making him feel miserable, before returning home to his country.
Boris is mentioned only in Fallout 4.