The Park Rapids Area Schools were the target of a computer network virus attack this week.
Superintendent Lance Bagstad said school staff noticed the problem Monday, and staff were warned not to log into their computers.
Bagstad said that Todd Kumpula, the school district's network administrator, has been working to rebuild their server files from backed up data.
"Todd has confirmed that our system was infiltrated with a ransomware virus," said Bagstad, meaning a hostile program that encrypts a computer's files and demands payment in exchange for the encryption key.
Bagstad noted that many other Minnesota schools have been hit with a ransomware virus this year.
"How it got in, we don't know yet," he said. "Right now, our concern is to work through solutions and rebuild our servers, which takes time and resources."
He said the school has gone on with business as usual, with the exception that the data on its servers has been encrypted. "So, we are restoring from backups the data that we already had," he said. "We didn't lose anything."
Bagstad confirmed that no private data was breached during the attack.
"Most of our software that we use is web-based, not hosted on site, like our student information systems and a lot of our educational software programs," he said, adding that these resources were not affected by the attack.
"For example, students use the cloud - Google Docs, Google Classroom. A lot of student documents are hosted in Google Drive. This has nothing to do with our system," he said.
He said teachers may be impacted if they kept documents backed up on the server rather than saving them to their desktop. "That's the problem right now; we can't access that," he said. "We can still teach. We just can't access our server files."
For another example, Bagstad said, "My laptop is running through our wireless system, going out (online) to do my work. I just can't access my server file. I have documents on there, but I don't need it daily to work. Really, it's just kind of an inconvenience."
Bagstad said school staff will reexamine its security protocols and discuss how to prevent future attacks once their system is back up and running.