CLOQUET, Minn. — Officials are still repairing computers in the Cloquet (klo-KAY') school district in northeastern Minnesota after a malware attack that was severe enough to close schools for one day.

Superintendent Ken Scarbrough says he thinks the attack started last week and got progressively worse. Then computer help icons started popping up, offering to fix the problem for a $6,000 fee.

Scarbrough says he believes an infected email attachment attacked the district's servers. So to give tech support staff a chance to start rebuilding the system, they closed all five schools in the district on Thursday. Full repairs will take weeks.

The bright spot, Scarbrough says, is no personal student or staff data or financial information is at risk.

Schools reopened Friday. The FBI is now working with the district's technology team.