For two consecutive days, a Distributed Denial of Service (DDoS) attack targeted the platform by overwhelming it with traffic, disrupting the exam schedules.
The cybercriminals are believed to have operated from 114 countries but failed to disable the system. The Ministry has reported the matter to a Supreme Court prosecutor, who has ordered a full judicial investigation.
Police's cybercrime division has been instructed to assist in the investigations.
“It is the most significant attack ever carried out against a Greek public or government organization,” the Education Ministry said, describing the incidents on Monday and Tuesday as “large scale and of sustained duration.”
End-of year high school exams in Greece are administered using an online platform known as the Subject Bank, designed to to set a uniform standard nationwide.