A system that thousands of schools and universities use was offline Thursday during a cyberattack, creating chaos as students tried to study for finals and underscoring education’s dependence on technology. The hacking group named ShinyHunters claimed responsibility for the breach at Instructure, the company behind the learning management system Canvas, said Luke Connolly, a threat analyst at the cybersecurity firm Emisoft. Instructure didn’t immediately respond to a request for comment or questions about whether the system was taken down as a precaution or because the hackers knocked it offline. The hacking group posted online that nearly 9,000 schools worldwide were affected, with billions of private messages and other records accessed, Connolly said. Screen shots he provided showed that the group began threatening Sunday to leak the trove of data, giving deadlines of Thursday and May 12. Connolly said the later date indicates that discussions regarding extortion payments may be ongoing.…