Canvas, a cloud-based learning management platform used by thousands of schools and universities, is back up after it was disabled for hours May 7.

Students attempting to access grades, study materials and quizzes were met instead with a message from a hacking group on Thursday.

Instructure, parent company of the education platform Canvas, said it took “immediate steps” to contain the hack before calling law enforcement.

An unknown group of hackers is breaking into systems previously breached by the cybercrime group TeamPCP. Once inside, the hackers immediately kick out TeamPCP and remove its hacking tools from the victims’ systems.

The Canvas hack forced some Massachusetts colleges to postpone final exams Friday.

Canvas is back online after a hack that impacted more than 8,000 schools and colleges across the country. (AP photo)

Universities across the country including UMass Lowell were hit by a computer hack to the Canvas Learning Management System, throwing campuses into chaos on Thursday just as final exams were taking place.

Graduating seniors at the University of North Carolina at Chapel Hill were left in limbo when the platform went dark on the final day of examinations, temporarily blocking access to grades and final projects.

A cybersecurity hack has made Canvas unavailable for Ohio State and Kent State students. A hacker group is demanding a ransom.