Vanderbilt University is responding to an “ongoing cybersecurity hacking incident,” the school said on Tuesday, following a message asking students, faculty and staff to “shut down university devices” one day earlier.

The Nashville-based university first posted a message on Monday warning students, faculty and staff members that the school was “responding to an active cybersecurity incident that may impact university devices, systems, and cloud-based services.”

The message urged university community members to watch out for suspicious activity on devices, including “unexpected pop-ups, warnings, or security notifications,” unusual changes with “files, folders, or permissions” in cloud storage platforms like Box or OneDrive, modification deletion or renaming of files unexpectedly, “unfamiliar applications, messages, or prompts appearing on your device,” or unexpected asks for passwords, authentication approval or credentials, as well as other strange behavior on devices.