The 2025 Cyber Security Breaches Survey found that 74% of large UK businesses experienced a cyber breach or attack in the previous 12 months. Phishing remained the most common attack type, affecting 37% of all businesses and 85% of businesses that reported a breach or attack.
These figures show why security teams need more than preventive controls. Organisations also need continuous visibility, clear ownership and the ability to investigate and contain incidents before they disrupt critical operations.
Managed Extended Detection and Response (MXDR) can support that operating model. By combining security telemetry, threat detection, investigation and response across endpoints, identities, cloud services and data, MXDR helps organisations move from reactive monitoring towards measurable resilience.
This article explains how Microsoft Sentinel, Microsoft Defender and managed security operations can contribute to that approach. It also considers the proposed Cyber Security and Resilience Bill and the practical steps organisations can take while the legislation continues through Parliament.
Traditional security controls remain useful, but they cannot identify every attack through a known signature or a single indicator. Attackers may use stolen credentials, legitimate administration tools, phishing, exposed vulnerabilities or weaknesses in third-party services. Once inside an environment, they may attempt to move between systems, escalate privileges and access sensitive data.
This makes behavioural analysis and cross-environment visibility increasingly important. A suspicious sign-in may appear low risk in isolation. When correlated with an unusual device, privilege escalation and activity across cloud applications, it may indicate a wider incident.
Security teams therefore need to bring together signals from the areas where attacks develop, including:
The objective is not to collect more alerts. It is to identify meaningful patterns, prioritise the incidents that require action and reduce the time between detection and containment.
Reactive security focuses on responding after an incident has become visible. A resilient operating model prepares the organisation to detect, contain and recover from disruption while maintaining important services.
That requires more than technology. It also depends on:
The value of MXDR is its ability to combine these elements with continuous monitoring and specialist expertise. It can provide additional capacity for investigation and response while allowing internal teams to focus on business priorities, architecture and longer-term improvement.
MXDR does not eliminate risk or guarantee uninterrupted operations. Its purpose is to improve the organisation’s ability to identify credible threats, make informed decisions and recover from incidents in a controlled way.
Microsoft Sentinel is a cloud-native security information and event management platform. It can collect and analyse data from Microsoft services, cloud platforms, on-premises systems and other connected sources.
Used effectively, Sentinel can help organisations:
Microsoft Defender provides detection and investigation capabilities across supported areas of the Microsoft security ecosystem. Depending on the products deployed, this may include endpoint, identity, email, collaboration and cloud workloads.
The combination can give security teams a broader view of an incident. For example, an alert involving a user account may be assessed alongside endpoint activity, email events and cloud application access. This context can help analysts distinguish a genuine compromise from an isolated or low-risk event.
The technology still requires careful implementation. Poorly configured data sources, excessive alert volumes and unclear response processes can reduce its value. A managed service can provide the operational discipline needed to tune detections, investigate incidents and improve coverage over time.
Many organisations cannot provide effective 24-hour monitoring with internal resources alone. Recruitment, specialist skills, shift coverage, training and retention all create practical challenges.
A managed detection and response service can provide:
The division of responsibility should be clear. The provider may investigate and contain activity within agreed boundaries, while the customer retains responsibility for business decisions, risk acceptance, communications and recovery priorities.
This operating model can help reduce alert fatigue without removing accountability. It also gives leadership teams a clearer view of which risks are being addressed, which require investment and where further evidence is needed.
The Cyber Security and Resilience Bill had progressed through the House of Lords as at 19 October 2026, but it had not yet received Royal Assent. The proposed legislation would amend the Network and Information Systems Regulations 2018 and broaden the regulatory framework.
The proposed changes include requirements affecting certain medium and large managed service providers, clearer treatment of cloud computing services and new obligations for qualifying data-centre operators. The applicable regime would depend on the services an organisation provides and the relevant thresholds and definitions.
Organisations should avoid treating the Bill as a current compliance requirement. They should, however, use the proposed direction of travel to review:
This assessment is particularly relevant for technology providers, managed service providers, cloud service providers and organisations operating critical or important services.
Organisations do not need to solve every security challenge at once. A structured assessment can identify the controls and operating processes that will have the greatest effect on risk.
A practical programme should consider:
This approach connects technical activity with outcomes that senior leaders can understand, including reduced exposure, improved service continuity and stronger evidence of control.
The appropriate model depends on the organisation’s risk profile, internal capability and operating requirements. Some organisations may manage Microsoft security technologies internally. Others may need a partner to provide continuous monitoring, specialist investigation or additional response capacity.
The key questions are:
A managed Microsoft security service can help organisations make better use of their existing technology investment while reducing the operational burden on internal teams. The provider’s value should be measured through outcomes such as improved visibility, faster investigation, better prioritisation and a clearer path to maturity.