father and grandfather. they previously targeted a south korean nuclear power plant, hacked the smartphones of top officials and allegedly carried out north korea's direct attack on north america on sony entertainment in the fall of 2014. they say they're good at grabbing hacking tools from the black market and breaking into targets. >> they don't have an i.t. industry. some days they don't even have electricity. both the current kim and his father put a big emphasis on i.t., on hacking. >> reporter: the report of a cyber attack comes at a time when the u.s. and south korea are bracing for another possible provocation from un. a time of political transition in the u.s. and political turmoil in south korea. the country consumed by a corruption scandal with president park geun-hye likely to resign or be impeached.