NHS ransomware attack: what happened and how bad is it?

One of the systems affected by the cyber-attack was ambulance dispatch. Photograph: Reuters

A ransomware attack on a software supplier has hit the NHS across the UK and there are fears that patient data may have been the target.

Advanced, the UK company hit by the attack last week, said it was working with government agencies, including the National Cyber Security Centre and the Information Commissioner’s Office, in the aftermath of the incident.