The first day of classes at Ponca City Public Schools in Oklahoma was set to start last Wednesday. Then they had a change of plans: A ransomware attack hit the school district’s servers the weekend before, pushing them to delay their opening to August 24.

The district’s learning management system, PowerSchool, suffered the attack. While no student, personnel or financial information was compromised, all their data was encrypted by the ransomware, says Superintendent Shelley Arrott in a video announcement.

Ransomware attacks continue to plague K–12 schools nationwide, and they’re not slowing down anytime soon. Since 2019, more than 1,000 educational institutions have fallen victim to ransomware, according to a report by security firm Armor. With most schools implementing some form of online instruction this school year, these attacks have only increased in volume and speed, and their impact is much more significant.