Nemzetbiztonsági Hivatal (NBH) (Office of National Security) is the name of a Hungarian secret service. Its primary responsibilities are defensive: counterintelligence, counter-terrorism, and related proactive measures. The Hivatal also leads investigations against organized crime and deals with (mainly internal) threats against society (such as political extremism).
It was reorganized after the fall of the socialist era in 1989, and it should now follow the modern law-based kind of information gathering and government support. Its previous incarnation has been part of the Ministry of Interior (Department III).