One afternoon in March 1962, Kulak walked into the FBI's NYC field office in broad daylight and offered his services.
In 1963, Kulak switched his KGB cover to science attaché at the Soviet Embassy, and continued working there until 1967, when he returned to Moscow.
[1] Although he had been considered a reliable source, by the end of his second tour, the FBI was beginning to suspect Kulak was secretly controlled by the KGB and was feeding false information to the Americans.
Still, before he left New York City, he was recruited by Gus Hathaway, the CIA agent who handled Adolf Tolkachev, to continue his espionage work for the Americans upon his return to Moscow.
[2] In 1977, back in Moscow, Kulak resumed contact with the CIA and provided a valuable list of Soviet scientists attempting to steal U.S. scientific secrets.
He promised to provide even more valuable sets of data about the inner-most workings of the KGB and the Soviet Union's efforts to steal American technology.
[2] A book by author Edward Jay Epstein published in 1978 described Fedora in enough detail to make it likely that the KGB was able to identify Kulak as the source.