New Delhi, May 31 -- The Central Board of Secondary Education's (CBSE) revaluation portal was hit by a "malicious cyberattack" that disrupted payment processing for around 50 Class 12 students and forced the board to defer the next phase of its re-evaluation process until the payment system was secured, education ministry officials said on Friday. According to a senior ministry official, the payment gateway linked to the CBSE's revaluation portal came under an unauthorised attack shortly after the system went live on May 19. "The malicious cyberattack affected the payment gateway infrastructure, resulting in incorrect fee displays during transactions. Around 50 students were affected. In some cases, the fee displayed was as low as Rs.1, while in others it shot up to nearly Rs.67,000-68,000," the official said. Speaking on the matter, a senior CBSE official, requesting anonymity, said, "The board is processing refunds for students who paid more than the prescribed fee because of the glitch." Officials confirmed that no student data was breached, and the attack was only concerned with the payment interface. The portal, used to obtain scanned copies of evaluated answer books and apply for re-evaluation, has remained unavailable since May 26. It was originally scheduled to reopen the same day for students to submit question-wise objections after accessing scanned answer sheets. The reopening was later postponed to May 29 and has now been rescheduled to June 1. CBSE officials said students who have already obtained scanned copies of their evaluated answer books will be able to submit question-wise objections once the portal reopens. The disruption came amid an unusually high volume of applications. Over 400,000 students sought scanned copies of their answer books between May 19 and May 25, accounting for nearly one-fourth of around 1.8 million students who appeared for the Class 12 board examinations this year, the officials said. As part of corrective measures, CBSE has removed HDFC Bank's payment gateway from the process and integrated payment systems of four public sector banks - State Bank of India, Canara Bank, Indian Bank and Bank of Baroda, the ministry officials said....