This seems like a good term to review following the revelation that during the Cold War, the CIA - dependent almost entirely on walk-ins - was misled by dozens of Soviet/Russian, East German, and Cuban double agents. The CIA's own hostility towards counterintelligence and the Soviet bloc's predilection for same had predictable results.
Agent-dvoynik — double agent
Agent working simultaneously for two or more intelligence services. The nature of the relationship between the double agent and the intelligence services may vary. The double agent may be working genuinely for only one service, hoodwinking the other by concealing his links with the first service and giving the appearance of collaborating genuinely with the second. Alternatively, he may not conceal his links with other intelligence services, while providing them with valuable information.
Agent-dvurushnik — double-dealing agent
Agent who pretends to be loyal to the counter-intelligence agencies while actually working for the enemy. Permission may be given for KGB agencies to use such agents, drawn from foreigners and from members of anti-Soviet groups and organisations, for purposes of disinformation.
Source: Mitrokhin, Vasili (2013-01-11). KGB Lexicon: The Soviet Intelligence Officers Handbook (p. 13). Taylor and Francis. Kindle Edition.
© 2015-2016 Andrew Aaron Weisburd