“There is a huge criminal cyber threat to law firms,” says Steve Hill, ex-deputy director in the UK Government National Security Secretariat dealing with cyber security. “The hackers perpetrating these types of attacks will not be teenage boys - they are criminal gangs set up to exploit law firms for sensitive data or lock people out of the data in return for a ransom.”

Hill, now a visiting senior fellow at King’s College London University, was closely involved in the UK Government’s cyber security policy in his previous role, and his comments highlight growing concerns around the vulnerability of personal and valuable data to cyber threats such as the recent WannaCry ransomware attack.