The school said on its website that it plans to re-open on Monday September 11 and “families have been informed of the reason for the delay to the autumn term”.
The school was initially scheduled to re-open on Tuesday September 5.
Computer systems at the Crouch End school have reportedly been taken down by the attack, causing confusion for online timetables, classes and homework.
According to the BBC, an email addressed to parents from the school, read: “With the help of Haringey Council, London Grid for Learning and other external experts in the field of cyber security, we’re doing everything to get our systems and functionality back up and running as swiftly and securely as possible.
“We sincerely apologise for any disruption and inconvenience this may cause you and your family and thank you for your patience, support and understanding at this time as we work through these IT issues.”
The email said the school is “extremely confident that our data has not been breached” but computer systems needed to be rebuilt to make sure there is no threat, Ham&High reports.
The Standard has approached Highgate Wood School for comment.