Health bosses in Suffolk have been responding to a report into the cyber attack which disrupted areas of the NHS in May.

The National Audit Office (NAO) has just released findings from its probe into the WannaCry attack which saw around 19,500 hospital appointments being cancelled nationally.

As well as cancelling appointments, five hospitals, including Broomfield Hospital in Chelmsford, were forced to turn patients away and more asked people to stay away from A&E departments.

GP surgeries were also infected by the bug which demanded bitcoin money from users.

The NHS had previously been warned by security experts that the operating systems on their computers were “ticking time bombs” with the report finding that many ran unsupported or unpatched computer systems that would have been vulnerable to this kind of malware attack.

In response to the report, Mike Bone, chief information officer for the West Suffolk NHS Foundation Trust, said: “We are not complacent, and continue to strengthen our protection against attacks. We have recently invested in a highly technical firewall platform and updated a number of software applications as part of our ongoing cyber security programme. In parallel we continue to develop our infrastructure, including physical hardware and software components, as we seek to minimise the opportunity for cyber events.”

Meanwhile, a spokesman at Ipswich Hospital said: “Everyone in the hospital works very hard to safeguard patient care and patient information.

“We were very lucky not to be affected in this incident but we are in no way complacent and will read the report and the recommendations made with great interest.”

A spokesman for NHS Improvement said the global cyber-attack was an “unprecedented worldwide event impacting thousands of computers and organisations”.

He added: “As with any incident of this kind, there are of course lessons that we can and will learn. But these shouldn’t take away from the hard work of staff from across the NHS.”

NHS Digital does not believe that any information was compromised or stolen during the attack though the Department of Health and NHS England said that they “do not know the full extent of the disruption” caused by it.