Canada’s University of Calgary paid almost $ 16,000 ($ 20,000 Canadian, ~£10,800) to recover crucial data that has been held hostage for more than a week by crypto ransomware attackers.

The ransom was disclosed on Wednesday morning in a statement issued by University of Calgary officials. It said university IT personnel had made progress in isolating the unnamed ransomware infection and restoring affected parts of the university network. It went on to warn that there’s no guarantee paying the controversial ransom will lead to the lost data being recovered.

“Ransomware attacks and the payment of ransoms are becoming increasingly common around the world,” Wednesday’s statement read. “The university is now in the process of assessing and evaluating the decryption keys. The actual process of decryption is time-consuming and must be performed with care. It is important to note that decryption keys do not automatically restore all systems or guarantee the recovery of all data. A great deal of work is still required by IT to ensure all affected systems are operational again, and this process will take time.”