Greece’s education ministry says it has been targeted in a cyberattack described as the most extensive in the nation’s history, aimed at disabling a centralised high school examination platform. It said the distributed denial of service, or DDoS, attacks aimed at overwhelming the platform occurred for a second consecutive day on Tuesday. The attack involved computers from 114 countries, causing outages and delays in high school exams but failing to cripple the system, the ministry said. The cyberattacks prompted a judicial probe ordered by a Supreme Court prosecutor, to be assisted by police’s cybercrime division. “It is the most significant attack ever carried out against a Greek public or government organisation,” the ministry said. The outages left students waiting in classrooms for hours for the exams to start.