By CBS3 Staff

DELAWARE COUNTY, Pa. (CBS) — Delaware County says critical systems have been restored following a computer hack that compromised part of its network last week.

The county says the security breach was caused by malware, and that they are working to determine what, if any, information was compromised.

READ MORE: Seven Years After Her Disappearance, Still No Traces Of What Happened To Amanda DeGuio

Sources tell Eyewitness News the hackers demanded a ransom to give up control of the network and that the county couldn’t access police reports, payroll, or other databases and files.

MORE ON CBSPHILLY.COM

READ MORE: Philadelphia Health Commissioner Dr. Thomas Farley Resigns Over Mishandling Of Remains Belonging To Victims Of 1985 MOVE Bombing

Stimulus Package Update: Lawmakers Announce Bipartisan Coronavirus Relief Plan

COVID In New Jersey: With Vaccine On Horizon, Gov. Phil Murphy Confident State Ready For Distribution

MORE NEWS: 2 Young Unresponsive Children Rushed To Hospital After Mother Jumps Out Window, Philadelphia Police Say

Police Asking For Help Identifying Suspect Believed To Behind Series Of Crimes In Montgomery, Camden Counties