CHICO, Calif. - The attackers hit Enloe Medical Center around 8 p.m. on the night of Jan. 3 causing administrators to shut down its network.
Director of Advancement and Communications Jolene Francis told Action News Now the attackers encrypted data - blocking Enloe from accessing it.
The cyber-attack also knocked out Enloe's phone systems.
Francis says Enloe disconnected many of the operating systems from the network and are slowly bringing them back up as they test them.
Local law enforcement and the FBI are working on the case.
Francis told Action News Now this attack is common for many businesses. She says 500 businesses reported a similar situation just last year.
ORIGINAL STORY: Cyber attack on Enloe Medical Center
She says there is no indication or evidence the hackers stole any patient information.
Employees say they're using pen and paper instead of their computers to log information.
And people coming out of Enloe said the shutdown isn't impacting the services, and it looks like business as usual.
Francis said at one point visitors were not allowed in as they assessed the situation, but even during the shutdown, they kept their doors open to patients in need.
Francis said the security for Enloe's network is solid.
It's monitored continually and they make any changes needed to deal with new cyber threats.
Francis says their system will improve as technology evolves.