CKC Network and Gakusan: ransomware attack on the inquiry system

On 2 May, CKC Network and Gakusan, which run cram schools and home tutoring, found a ransomware attack on the server of the inquiry management system they operate together and shut it down. The second report on 10 June said a vulnerability in server management software was exploited. The server held about 664,000 inquiry records (names and school years; about 9,900 may include phone numbers, addresses or emails) and about 53,000 member records (member numbers and family names). No sign of data being taken was found.