Cyber Resilience Audit - the ultimate test for Critical National Infrastructure

This isn’t theoretical. We’ve already seen it play out: in 2017, the NHS WannaCry attack paralysed hospitals across the UK, delaying treatment and costing the taxpayer £92 million. In 2021, the Colonial Pipeline ransomware attack shut down nearly half the fuel supply to the US East Coast, sparking shortages and economic disruption.

These incidents prove that the threat to our Critical National Infrastructure (CNI) is real and growing. When the systems that power our lives come under attack, cyber security stops being a background concern. It becomes mission-critical.

What is a Cyber Resilience Audit?

A CRA is a structured assessment of how well an organisation can prepare for, respond to and recover from cyber incidents. It’s designed for use by Critical National Infrastructure organisations to allow them to rate, understand and improve their cyber defence and response capabilities.

It’s built on the Cyber Assessment Framework (CAF) - a practical set of standards that goes beyond compliance to focus more on actual-world resilience. Its objective is clear: identify risks, close vulnerabilities and ensure critical operations continue even under active attack.

The cost of being unprepared

CNI has always been a prime target for attackers. The rewards for disruption are high and the consequences can be devastating.

In 2012, a cyber attack on Saudi Aramco, the world’s largest oil company, wiped data from 30,000 computers and forced staff back to pen and paper. It remains one of the most destructive cyber incidents on record and revealed just how fragile global energy security can be.

More recently, in 2021, the Irish Health Service Executive was crippled by a ransomware attack that forced a nationwide IT shutdown. Patient care was severely disrupted, cancer treatments were delayed with the total recovery cost exceeding €53 million.

These examples underscore a simple truth: cyber incidents don’t just disrupt IT systems - they spill over into the physical world, affecting businesses, governments and everyday lives.

Regulations like the NIS Regulations are raising the bar, but meeting the minimum standard is only the start. A CRA helps organisations go further - shifting from a “compliance achieved” status to a culture of resilience assured.

Strength through testing

The CRA process is clear, targeted, and actionable. It follows these core pillars:

1. Scoping - pinpoints the systems, data, and processes where a failure would have the greatest impact.

2. Assessment - tests how well threats are identified, defences hold up, and recovery plans work under pressure.

3. Reporting - delivers clear, prioritised actions that strengthen resilience where it matters most.

At every stage, the aim is the same: a clear picture of your readiness and a practical path to making it stronger.

Who’s mandated to undertake a CRA?

While CRAs are designed for CNI sectors - energy, healthcare, transport, water, finance, and communications - they’re equally relevant for suppliers to these sectors. In a connected ecosystem, a single weak link in the supply chain can compromise the resilience of the entire network, making supplier audits just as critical as those for CNI operators.

CRAs are delivered exclusively by NCSC-accredited auditors - like Instil. Our team knows the CAF inside-out, understands sector-specific challenges, and focuses on one key question: Can you actually withstand an attack?

Five reasons a CRA is worth it

A CRA should not be viewed as a checkbox exercise. Done properly, it will result in positive change:

• Stronger defences - Close vulnerabilities before attackers find them.

• Regulatory confidence - Meet and exceed security requirements.

• Lower risk - Reduce exposure through early intervention.

• Public trust - Demonstrate a visible commitment to security.

• Ongoing improvement - Track progress and keep raising resilience levels.

Resilience is non-negotiable

Cyber resilience ensures essential services keep running, no matter the threat. It’s about safeguarding people, protecting the economy and maintaining trust. A CRA is one of the clearest, most effective ways to prepare for whatever comes next.

The bottom line: The cyber threat to CNI is growing fast. A Cyber Resilience Audit gives you the clarity, structure and expertise to find weaknesses, strengthen defences, and keep vital services running. For organisations in critical roles, it’s not a “nice to have” - it’s part of the job.

Instil is an NCSC-accredited auditor, trusted to deliver Cyber Resilience Audits to the highest standard. Ready to take a decisive step towards resilience assured? Talk to us.