EU Banking Regulator Hit By Microsoft Email Hack EU Banking Regulator Hit By Microsoft Email Hack Microsoft said last week that a state-sponsored group operating out of China was exploiting previously unknown security flaws in its Exchange email services to steal data from business and government users. The "Hafnium" group was a "highly skilled and sophisticated actor," it said. (Representational) Paris: The European Banking Authority, a key EU financial regulator, says it has fallen victim to a hack of its Microsoft email system which the US company blames on a Chinese group. Microsoft said last week that a state-sponsored group operating out of China was exploiting previously unknown security flaws in its Exchange email services to steal data from business and government users, believed to number in the tens of thousands so far.