The Ofcom hack is the latest in a string of MOVEit victims which includes IAG SA's British Airways and the British Broadcasting Corporation.

Ofcom spokesman said that a limited amount of information about certain companies it regulated -- some of it confidential -- along with personal data of 412 Ofcom employees, was downloaded during the attack.

"We took immediate action to prevent further use of the MOVEit service and to implement the recommended security measures. We also swiftly alerted all affected Ofcom-regulated companies, and we continue to offer support and assistance to our colleagues."