Between 18 March 2019 and 1 December 2020 Interserve Limited (“Interserve”) failed to process personal data in a manner that ensured appropriate security of the personal data using appropriate technical and organisational measures as required by Article 5(1)(f) and Article 32 GDPR. This rendered Interserve vulnerable to a cyber-attack which took place in the period 30 March 2020 to 2 May 2020 and affected the personal data of up to 113,000 employees of Interserve.