One of Seattle's largest advertising agencies has merged with three agencies in Europe and Asia. The Hacker Group merged Thursday with DraftFCB Munich's offices in Munich, Prague and Shanghai, said Spyro Kourtis, Hacker Group president. DraftFCB Munich is part of DraftFCB. The combined group of more than 300 employees is rebranding as HackerAgency and will report directly to Carter Murray, the CEO of FCB. Kourtis will be president and CEO of the combined organization, and Stephan Horvath, formerly…