NHS Hacking Attacks: What Happened & How to Prevent the Next Crisis

The NHS has faced a series of high-impact hacking attacks in recent years — from the infamous WannaCry ransomware outbreak in 2017 to the Synnovis pathology breach in 2024 and the Ivanti EPMM exploit in 2025. Each cyberattack has revealed how fragile healthcare infrastructure becomes when third-party risks, weak segmentation, and legacy systems collide.

If you’re looking for current NHS cyber incident updates or official guidance, visit digital.nhs.uk/cyber or check your local NHS Trust’s service status page.

This article breaks down what happened, the technical attack patterns, and—crucially—what the NHS and other healthcare organisations must learn to avoid the next crisis.

The NHS Cyber Incidents

WannaCry (2017): Legacy systems cripple frontline care

WannaCry spread globally by exploiting the EternalBlue SMBv1 vulnerability, a flaw in Microsoft Windows that had already been patched. Many NHS systems were still running unpatched, unsupported versions, allowing the ransomware to propagate within hours. Hospitals cancelled appointments, ambulances were diverted, and patient records became inaccessible.

The National Audit Office investigation detailed how the NHS’s reliance on outdated operating systems and incomplete patching left it exposed. The NCSC ransomware guidance remains a key reference for hardening similar systems.

Lesson: Patch management is essential. When patching is not possible due to legacy dependencies, segment legacy assets and apply compensating controls such as application whitelisting, restricted network zones, and offline backups.

Synnovis Breach (June 2024): Pathology provider takedown

In June 2024, Synnovis, a major pathology supplier to the NHS, suffered a ransomware attack that disrupted blood testing across London hospitals. The attack impacted King’s College Hospital and Guy’s and St Thomas’ Trusts, forcing the cancellation of surgeries and delays in diagnosis. NHS England confirmed the incident in an official statement, with further coverage by Reuters.

Forensics indicated the use of a ransomware variant targeting on-premise infrastructure and network shares, likely enabled through compromised supplier credentials or exposed administrative interfaces. The incident underscored how single suppliers can become national points of failure for healthcare delivery.

Lesson: Supplier compromise equals patient risk. NHS trusts must inventory supplier access paths, enforce least privilege, require zero-trust connections, and design fallback resilience plans such as alternative labs or manual contingencies.

Ivanti EPMM Exploit (May 2025): Management tool as an attack vector

In May 2025, attackers exploited vulnerabilities in Ivanti Endpoint Manager Mobile (EPMM), used by some NHS trusts to manage staff mobile devices. The exploit combined an authentication bypass with remote code execution, granting access to sensitive staff data and device configuration systems.

This incident highlighted the risk of centralised management planes, where a single misconfiguration or unpatched admin interface can compromise an entire environment. For context, see reporting in Digital Health.

Lesson: Harden the management plane. Keep MDM and other remote administration systems behind private access gateways. Require hardware-based MFA, rotate admin credentials regularly, and continuously monitor privileged session activity.

Shared Attack Patterns Across NHS Incidents

Each NHS breach looks different on the surface, but they share striking technical similarities:

• Third-party compromise through suppliers or management tools

• Known but unpatched vulnerabilities

• Credential or session theft

• Weak network segmentation and lateral movement

• Single points of failure in centralised systems

For policy and technical mitigations, see the NCSC Supply Chain Security Collection.

A related example comes from consumer genomics: our 23andMe breach deep dive showed how credential stuffing and data-linkage features can exponentially increase breach scope—a lesson equally applicable to healthcare ecosystems.

Beyond the NHS: Other Healthcare Breaches

The NHS is not alone in facing these challenges. Similar incidents worldwide reveal the same underlying patterns:

• Change Healthcare ransomware (US, 2024–2025): A crippling supply-chain attack that disrupted nationwide billing and payments. See the HHS OCR FAQ and Reuters coverage.

• SingHealth breach (Singapore, 2018): Attackers exfiltrated data of 1.5 million patients due to unpatched systems and inadequate monitoring. The Committee of Inquiry Report remains one of the most detailed healthcare breach analyses available.

• Advanced supplier breach (UK, 2022): A non-clinical IT vendor breach cascaded into NHS systems, showing that every connected supplier—even outside direct care delivery—can be an attack vector. See the ICO enforcement summary.

  
  

These events reinforce a fundamental truth: healthcare is uniquely vulnerable because legacy technology, complex supplier networks, and always-on clinical operations converge.

What Needs to Change

Technical priorities for NHS and suppliers

• Supplier governance: Conduct annual security audits, enforce attestations, and restrict supplier access using just-in-time and least-privilege models. Align contracts with NCSC supply chain principles and DSP Toolkit requirements.

• Harden administrative systems: Isolate MDM, SSO, VPN, and ITSM tools from public access. Require hardware-based MFA and real-time monitoring of privileged activity, especially for management systems like EPMM.

• Patch and isolate legacy systems: Prioritise patching for high-risk CVEs. Where patching is clinically constrained, segment networks, use virtual patching via IPS/EDR, and follow NCSC ransomware resilience guidance.

• Identity and session security: Rotate secrets and API keys, detect token theft, and validate session integrity. Enforce device posture checks for administrative access.

• Detection and resilience: Centralise telemetry, deploy EDR across endpoints, and conduct regular tabletop exercises simulating supplier failure or data extortion. Validate restore procedures against clinical priorities.

  
  

Where Sekurno Can Help

Sekurno specialises in cybersecurity for high-risk, compliance-heavy industries such as healthcare and life sciences. For NHS trusts and suppliers, our services directly address the vulnerabilities exposed by these incidents:

• Penetration Testing & Red Teaming — uncover vulnerabilities in applications, APIs, and infrastructure before attackers do.

• Application Security & Secure SDLC — integrate threat modeling, code review, and DevSecOps practices into software delivery.

• Compliance & Supplier Assurance — align with ISO 27001, GDPR, and the NHS DSP Toolkit to ensure robust security and compliance maturity.

  
  

For a sector-wide perspective on recurring risks in biotech, read our Biotech Cybersecurity Report 2025. If your operations involve PHI or US healthcare systems, explore our HIPAA-aligned penetration testing.

Final Thoughts

Cyberattacks on the NHS and healthcare systems worldwide show that cybersecurity is no longer a back-office IT issue. Disruption doesn’t just mean downtime or financial loss; it can mean cancelled treatments, delayed diagnoses, and patient harm.

By strengthening supplier governance, network segmentation, patch management, and incident readiness, the NHS can evolve from fragile to resilient. Cybersecurity in healthcare is not a compliance exercise, but a patient safety imperative. Protecting systems means protecting lives.