Principal Security Researcher

Security is one of the most critical priorities for our customers in a world of growing digital threats, regulatory scrutiny, and estate complexity. Microsoft Security aspires to make the world safer by empowering every user, customer, and developer with a security cloud that delivers end-to-end, simplified protection. The Microsoft Security organization advances this mission by helping secure digital technology platforms, devices, and clouds across customers’ heterogeneous environments, while also protecting Microsoft’s internal estate. Our culture is grounded in a growth mindset, inspiring excellence, and enabling teams and leaders to bring their full potential each day. 

The Microsoft Threat Protection Research (MTP-R) Purple Team sits at the intersection of offense, defense, and intelligence, working across Microsoft Defender technologies to ensure telemetry, detections, and protections are effective against real-world cyberattacks. We are looking for a principal-level security researcher with deep experience in threat operations and Defender tooling to help design, execute, and analyze advanced adversary simulations, collaborate with engineering and detection teams, and translate attacker tradecraft into measurable defensive improvements across Microsoft’s security stack. This role is expected to operate in an AI-first environment, leveraging agentic systems and LLM-driven workflows to scale simulation design, automation, and validation beyond traditional human-driven approaches.