Hackers have used ransomware to encrypt files at a Dorset school causing it to lose some students’ GCSE coursework.
The Sir John Colfox Academy, Bridport, said a member of staff mistakenly opened an email containing a virus.
The email claimed to be from a colleague at another Dorset school and infected the school’s computer network.
The school said coursework from one subject submitted by Year 11 students, which had been saved on the school network, was currently lost.
Head teacher David Herbert said: “We are liaising with the relevant exam boards about this specific issue.”
Mr Herbert added a police expert “has advised us that it is very unlikely that any school information has left the building and we are not compromised in that way”.
“Personal data relating to staff, students and parents is not held on this system and is secure,” he said.
The school said specialists were working to try and rectify the issue, which also means Year 9 and 10 reports will be delayed by at least a week.
Dorset Police said: “A full investigation is under way into the circumstances and Dorset Police’s cyber crime unit is supporting and providing advice to the school.”
The force said no money had been exchanged.