A central Indiana health network says it has paid ransom worth about $55,000 to hackers to regain access to hospital computer systems.

Hancock Health in Greenfield says in a statement the attack was initiated Thursday by an "unidentified criminal group." Hancock says it was able to recover the use of its computers and found no evidence any patient information was adversely affected.

The Daily Reporter of Greenfield reports more than 1,400 files were targeted and the health system was given seven days to pay in bitcoins. The newspaper says that at the time of the transfer the payment totaled about $55,000 worth of the virtual currency.

Hancock's CEO Steve Long tells WRTV the ransom was paid "to expedite our return to full operations." The health system includes Hancock Regional Hospital.