The Billericay School in Essex said its systems were compromised during the half-term holiday.
He said the school would be closed to pupils in Year 7, 8, 9 and 12 on Monday so staff could prepare lessons while they did not have access to their resources on the system.
The incident followed a BBC report which revealed 347 cyber incidents were reported in the education and childcare sector in 2023 - an increase of 55% on 2022.
Government data suggested most schools and colleges have identified a cyber-security breach in the past year.
Some told the BBC it led to temporary closures and weeks of disruption.
This Cyber News was published on www.bbc.com. Publication date: Sun, 02 Jun 2024 23:29:04 +0000