Students were unable to access Canvas on Thursday afternoon after cybercrime group ShinyHunters shut down Penn’s access to the interface.

The May 7 data breach comes after ShinyHunters — notorious in the hacking community for large-scale data breaches — claimed responsibility for breaching Instructure, the company that manages Canvas, last week. In the message posted on Penn’s Canvas page, the hackers wrote that any university that does not wish to have its data released should contact the group before May 12.