Investigation WannaCry cyber attack and the NHS

This National Audit Office investigation of the May 2017 WannaCry ransomware attack on NHS England finds that at least 81 of 236 trusts and hundreds of GP practices were affected, causing widespread disruption (an estimated ~19,000 appointments impacted, diagnostic equipment and some emergency services disrupted); the report attributes the spread to unpatched or unsupported Windows systems and poor perimeter controls, notes that a researcher-activated kill-switch limited further damage, and sets out failings in preparedness, response coordination and oversight while recommending improved patch management, firewall controls, incident planning and central assurance.