North Korean hackers may have stolen a large amount of classified military documents, including the latest South Korea-US wartime operational plan, Yonhap reported Tuesday, citing a South Korean ruling party lawmaker. Democratic Party representative Rhee Cheol-hee claimed that 235 gigabytes of military documents were taken from the Defense Integrated Data Center. The contents of about 80 percent of the data have not yet been identified, Yonhap said, adding that the hack took place in September last year. Pyongyang has denied responsibility for the cyberattacks, criticizing Seoul for “fabricating” claims about online attacks, Reuters said.