Alastair Gale and Kwanwoo Jun write the South Korean national police agency said the cyber incidents also led to the theft of approximately 2,000 communications systems-related documents.
A spokesman for Hanjin Groupâs subsidiary Korean Air Lines Co. said the stolen files included designs for the wings of an F-15 fighter aircraft and pictures of parts of unmanned reconnaissance planes, the newspaper reported.
A military official in South Korea said the stolen documents were not classified and âwill likely have a negligible impact on national security,â according to the report.
âNorth Korea turns out to have been preparing for a long time to try to launch a countrywide cyber attack,â the South Korean police agency said.
Jack Kim also reports for Reuters the data breaches at two South Korean conglomerates — Hanjin Group and SK Holdings — are part of a larger cyber attack campaign that North Korea launched in 2014.
North Koreaâs cyber hacking campaign was detected in February and compromised over 140,000 computers at 160 government agencies and companies in South Korea, the report said.
A spokesman for SK Holdings said the cyber attack affected four of its group affiliates.
Police officials told Reuters they traced the hack to an internet protocol address based in Pyongyang, North Korea, that zeroed in on network management software used by government agencies and private firms.
They also found that the IP address was similar to the one used in a 2013 cyber attack on computer networks of South Korean banks and broadcast stations, Kim reports.