Digital attacks on Kennewick School District servers affected student testing in schools around the district this week.
"We don't know whether it's malware or someone doing it intentionally," said Ron Cone, the district's information technology director.
The servers were crashed by what looks like "denial-of-service" attacks at least once a day, with the system going down five times on Friday.
The crashes won't affect the test results students need to meet state requirements, because state-mandated testing wrapped up weeks ago, district officials said.
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The affected tests are for the district's own purposes of tracking student growth and performance.
"It didn't really affect us too much. We all finished on time," said district spokeswoman Robyn Chastain.
However, Cone said he and his staff are working to protect the system and find the source of the attack.
The attacks are flooding the servers with Domain Name System, or DNS, requests, overwhelming them and causing them to crash. Other districts in the state have reported similar attacks in recent months, Cone said.
While the district will try to isolate the problem to protect the district's network, Cone said they also want to bolster the district's firewall to halt the attacks.
The server crashes are the latest computer-based problem to face the district.
Kennewick school employees have been battling an erratic email system for weeks, requiring parents, teachers and administrators to rely more on the district's phones.
Computer manufacturer Dell and software publisher Microsoft even delved into the email problem.
The district is currently moving all district email to new servers to eliminate the issue, and Cone said that project should be finished in mid-June.