The University of Maryland Medical System was hit with a ransomware attack earlier this week that affected a small number of its medical devices offline.

About 250 of the system’s 27,000 devices were impacted by the attack, The Baltimore Sun reported. However, a hospital spokesman told The Sun the devices were not encrypted, as is the case with most ransomware, so the ransom was not paid.

The attack began on Dec. 9 at 4:30 am forcing the hospital to take its networks and devices offline by 7 am. The 250 infected devices, mainly desktop computers were quarantined and all the other equipment was put back online Monday morning, The Sun reported.

“The measures we took to identify the initial threat, isolate it to prevent intrusion, and to counter and combat the attack before it could infiltrate and infect our network worked as designed,” said Jon P. Burns, Senior Vice President and Chief Information Officer for UMMS.  “None of our systems were encrypted with a ransomware-type virus, and at this time, we have no indication that any patient data or records were compromised.”