Strengthening Cyber Resilience in the UK Utilities Sector

How a leading utility provider is fortifying its IT and OT infrastructure with Microsoft Sentinel and Telefónica Tech.

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Case Studies | 26 March 2025

The challenge

Delivering essential services, securely

A major UK utility provider, managing critical national infrastructure, faced increasing cyber security threats, including the risk of state-sponsored attacks. The organisation required a Microsoft Sentinel and SOAR solution to protect both its corporate IT and operational technology (OT) estate. Following a rigorous RFP process, they selected Telefónica Tech as a strategic security partner to drive their evolving cyber resilience strategy.

With a vast operational footprint and responsibility for delivering essential services to millions, the organisation required a security solution capable of scaling across its extensive infrastructure, ensuring uninterrupted service delivery while mitigating evolving cyber risks.

Sentinel-first security approach

Telefónica Tech is working closely with the organisation to implement a Sentinel-first security approach, ensuring seamless integration within their evolving cyber security ecosystem. The engagement includes:

Microsoft Sentinel & XDR Security Operations

Delivering real-time security visibility across IT and OT environments through a unified console.

Dedicated Virtual SOC (vSOC)

A team of Level 1 analysts, Level 2 engineers, and Level 3 security architects ensuring end-to-end protection and incident response.

Seamless Customer-Owned Security Deployment

Implemented within the customer’s own Microsoft subscription, ensuring full IP ownership and compliance.

Microsoft Native SOAR Automation

Leveraging built-in security orchestration to reduce risk and accelerate incident resolution.

Advanced Threat Intelligence

World-class insights from Telefónica Tech’s Cyber Threat Intelligence Team, enhancing proactive threat hunting.

Collaboration with Key Partners

Working within a Service Integration and Management (SIAM) framework, ensuring smooth governance and operations.

UK-Based Service Delivery

While global centres deliver security operations, UK-based teams ensure compliance and governance.

Continuous Service Improvement

A structured approach focused on ongoing security enhancements and proactive risk mitigation.

The Outcomes

Continuity of critical operations

Seamless Transition: The transition to a co-managed Microsoft Sentinel model is progressing smoothly, strengthening the organisation’s security posture in real time.

Strengthened Cyber Resilience: Enhancing security across IT and OT, reducing exposure to advanced cyber threats.

Operational Efficiency: Automation-driven security response reducing manual intervention and accelerating threat containment.

Long-Term Security Partnership: Telefónica Tech is embedded within the organisation’s security framework, ensuring scalability for future cyber security needs.

By securing a major national service provider responsible for delivering essential services to millions, Telefónica Tech’s approach ensures not only cyber resilience but also the continuity of operations critical to communities across the UK.

Customer Quote

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"Telefónica Tech’s security-first approach and deep expertise in Microsoft Sentinel are already making a significant impact on our cyber resilience, providing us with a future-proofed security operations model."

CIO, One of the largest Water Utilities in the UK