BREWER, Maine — The Brewer School Department paid $1,400 to unlock its computers after an employee apparently clicked on a link that allowed a “ransomware virus” to corrupt the system, Superintendent Cheri Towle said Friday.

The malware that locked up the system Wednesday came with a demand for $1,400 to decrypt the department’s files, she said. The ransom was paid in bitcoin, an anonymous online currency.

“After consulting with the Maine state crime lab, they recommended we pay to get our data back,” she said. “After involving the Maine State Crime Lab with the help of the Brewer Police Department, they assisted us in how to obtain the encryption code.”

No student or personnel information was compromised, she said.

“We immediately shut down our wireless system and controlled the threat,” she said. Still, “a lot of our files are encrypted and we can’t access them right now.”

The department is trying to restore its computer system by decrypting each server, as well as individual files on computers that were hit. Towle said the system should be back online by early next week.

School leaders in Brewer can still access their emails using their cellphones, and have been communicating via text messaging, she said.

That attack came the same week that ransomware in Britain blocked access to computers and forced hospitals to cancel surgeries, the Washington Post reported. That malware exploits a flaw in Microsoft software, and is called ransomware because it encrypts systems and threatens to destroy data if a ransom is not paid, according to the Post.

The Maine Crime Lab informed the Brewer superintendent that in 9 out of 10 ransomware attacks victims “have to pay it as there is no other way to get your data unlocked,” Towle said.

Calls to Brewer police and Maine State police were not immediately returned.

The department is reviewing its security to prevent future attacks, and whether the ransom is covered by its insurance.

The Houlton, Boothbay Harbor, Damariscotta, Wiscasset and Waldoboro police departments — as well as the Lincoln County Sheriff’s Office — are among the other Maine institutions that have forked over money to regain access to their computer files, according to published reports.

BDN writer Dawn Gagnon contributed reporting