A military-grade cyberattack seized the Port of Kennewick’s computer system on Nov. 16, cutting off email and other systems.

Email was restored by the end of the month but port staff were still working to restore functionality to their computer systems in early December.

The port refused to pay a $200,000 ransom to restore access to its servers, which were encrypted by sophisticated digital “military-grade” ransomware.

The Federal Bureau of Investigation and the Washington State Office of Cybersecurity investigated.

A contractor worked to restore the port’s system to re-establish email and other services using digital files from offline backups.

The port said personal information were not compromised.

The port uses a professional IT firm to maintain and secure its servers. It said its systems were well maintained and that it runs regular scans to ensure it had the appropriate systems in place.

The port contracts with a separate, independent consultant to advise the port on technology and IT systems.