BUFFALO, N.Y. -- During this Easter weekend, Erie County Medical Center (ECMC) IT technicians, hospital staffers and various consultants have been hard at work trying to restore the hospital's computer system. 

The system was shut down about a week ago after a virus was detected. 

Since the computer virus was found in the early morning hours of Sunday, April 9th, ECMC spokesman Peter Cutler says 6,000 hard drives were cleansed and then re-installed in desktops throughout the hospital. 

They also had to make sure vital information like data on patients' electronic medical records was not affected -- so far the hospital says there is no evidence it was, and Cutler says he is confident patient information is safe.

While medical procedures and treatment have been ongoing, it's been a back-to-basics approach. 

"The information on patients and the care that's been provided uninterrupted since last Sunday is still being done manually, which will then ultimately be reconciled and put back in the system once it's fully operational," Cutler said. 

A probe into what happened with assistance from a specialized cybersecurity firm, called Greycastle in Rochester, is also ongoing. 

Last week, two sources said ECMC was the target of a ransomware attack and tens of thousands of dollars were requested by hackers to restore information on the hospital's computers. Apparently, a backup storage system for files was used and experts say that is a way to avoid paying the ransom. ECMC has not yet formally confirmed that the virus was ransomware.

A hospital in California actually paid a ransom of $17,000 in a similar incident last year. 

When asked if any payment was made to hackers, Cutler said: "I assure you there's been no such action. However, the whole aspect of that circumstance is still under investigation." 

Hospital officials held on conference on Easter Sunday, despite the holiday, to keep working on the problem.

ECMC's website is back online as of Friday.