Security Researcher - Cybersecurity Infrastructure Engineer

As a Cybersecurity Infrastructure Engineer, you will lead and support evidence-driven infrastructure response, identity recovery and technical hardening workstreams across enterprise on-premises and cloud environments.

• Set infrastructure recovery objectives, technical priorities and evidence requirements for identity, directory, privileged access and enterprise infrastructure workstreams.
• Lead or support containment and recovery for compromised Active Directory, Entra ID, Tier 0 and hybrid infrastructure environments.
• Assess compromise scope, recovery readiness, trust relationships, privileged access pathways and security-control gaps; establish what is known, what remains uncertain and what additional validation is needed.
• Direct or guide technical response activities that balance containment, recovery urgency, evidence preservation and customer business constraints.
• Collect, preserve and analyse infrastructure and identity evidence needed to support investigation, containment and recovery decisions.
• Serve as a technical point of contact for infrastructure recovery; brief customer technical teams, executives and internal stakeholders with clear findings, priorities and decision options.
• Maintain technical documentation and clear follow-the-sun handovers covering evidence, decisions, risks, dependencies and next actions; support final reporting and lessons learned.

• A relevant degree in Computer Science, Computer Security, Statistics, Mathematics or a related field, or equivalent practical experience in cybersecurity, infrastructure engineering, incident response or related operations, and of industry experience.
• Demonstrated hands-on experience with Active Directory, Entra ID or other enterprise identity platforms in complex enterprise environments.
• Understanding of identity-related attack techniques.
• Experience supporting identity recovery, infrastructure recovery and post-breach hardening decisions under operational pressure.
• Familiarity with Windows Server infrastructure, DNS, DHCP, Group Policy, privileged access and hybrid identity dependencies.
• Ability to script or automate recovery, validation or analysis tasks using PowerShell or similar tools.
• Demonstrated ability to explain technical findings, dependencies, risk and residual uncertainty clearly to customers and internal stakeholders.
• Flexibility to work non-standard business hours that may include evening, nighttime, weekends and/or holidays.

Preferred Qualifications

• Experience in cybersecurity incident response, digital forensics, threat hunting or enterprise recovery.
• Familiarity with Microsoft Defender XDR, Microsoft Sentinel, Entra ID, Microsoft Graph, Azure, Windows security eventing and third-party SIEM/SOAR or EDR platforms.
• Experience leading infrastructure workstreams in high-pressure, customer-facing incident response while balancing investigation, containment and recovery needs.
• Demonstrated ability to translate technical constraints into practical response plans and executive-ready recommendations.
• Relevant security, identity, cloud or incident response certifications, or equivalent practical expertise.
• Demonstrated research, analytical automation, data-quality improvement or technical mentoring that strengthens infrastructure response capability.

Security Clearance Requirements

The successful candidate should have or be able to obtain the Security Check (SC) or Developed Vetting (DV) clearance as issued by the United Kingdom Security Vetting Unit (UKSV). Ability to meet Microsoft, customer and/or government security screening requirements are required for this role.

With more than 45,000 employees and partners worldwide, the Customer Experience and Success (CE&S) organization is on a mission to empower customers to accelerate business value through differentiated customer experiences that leverage Microsoft products, services and partnerships.

Microsoft’s Detection and Response Team (DART) is seeking a skilled and experienced Cybersecurity Infrastructure Engineer to join the team. DART is the first port of call for many customers during a security incident. This pivotal, customer-facing position helps customers contain, recover from and build resilience against high-impact cybersecurity incidents.

You will lead infrastructure recovery and identity containment workstreams, establish technical priorities and act as a trusted technical partner for customers during urgent response activity. Working with lead investigators, threat hunters, reverse engineers and incident coordinators, you will help customers make evidence-led recovery decisions and improve security outcomes.

As part of a globally distributed, mission-driven team, you will share practical recovery expertise, mentor colleagues and help shape the future of Defender Experts Cybersecurity Incident Response.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. Employees are expected to demonstrate a growth mindset, innovation, collaboration, respect, integrity, accountability and inclusion.