Principal Security Engineer

• Execute CyberShield red team operations end-to-end - initial access, privilege escalation, lateral movement and pivoting, persistence, objective completion, and reporting - against Microsoft’s own environment and select external customer environments, using real-world adversary tactics, techniques, and procedures to validate detection, investigation, and response.
• Develop custom tooling, implants, and tradecraft to evade modern defenses and emulate the capabilities of advanced adversaries.
• Lead agentic red team operations: design and direct AI agents that autonomously perform reconnaissance, vulnerability discovery, exploitation, and post-exploitation; define guardrails, oversight, and human-in-the-loop checkpoints; and drive the shift from human-led execution to continuous, software-driven, agentic analysis.
• Discover and exploit vulnerabilities end-to-end across application, cloud, identity, network, hardware, and operational security layers, chaining findings into realistic attack paths that demonstrate business impact.
• Serve as the forward-deployed technical lead with customers: brief CISOs and security leaders, translate findings into actionable narratives, and deliver lightweight defensive engineering guidance alongside offensive results.
• Prototype and productionize tools, agents, and techniques that scale offensive emulation and vulnerability discovery, and feed requirements back to our offensive AI platform engineering team based on what works in real environments.
• Collaborate with Blue Teams, GHOST (Microsoft’s adversary hunting organization, which proactively hunts for and responds to real-world intrusions in Microsoft and customer environments), MSTIC (the Microsoft Threat Intelligence Center, which tracks nation-state and criminal threat actors and their tradecraft), and internal Microsoft service teams to convert findings into product hardening and improved defender readiness.
• Set operational standards and playbooks for CyberShield engagements; mentor senior operators and virtual-team specialists drawn from across MRT.
• Advocate for security change across Microsoft and its customers by building partnerships and clearly communicating the impact of risk.
• Embody our Culture and Values.

• Master’s Degree in Statistics, Mathematics, Computer Science, or related field AND 6+ years experience in security or related field OR Bachelor’s Degree in Statistics, Mathematics, Computer Science, or related field AND 8+ years experience in security or related field OR equivalent experience., * Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include, but are not limited to the following specialized security screenings:
• Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter.
• Customer environment screening: Operators working in customer environments may be required to complete additional customer- or government-directed vetting., * Master’s Degree in Statistics, Mathematics, Computer Science, or related field AND 8+ years experience in security or related field OR Bachelor’s Degree in Statistics, Mathematics, Computer Science, or related field AND 12+ years experience in security or related field OR equivalent experience.
• 6+ years of experience planning and leading red team or adversary emulation operations against enterprise or cloud environments.
• Demonstrated hands-on experience building, directing, or operating AI-driven or agentic offensive security tooling in real operations. Active U.S. Government TS//SCI clearance with full-scope polygraph is a strong plus, enabling immediate work with our most sensitive customers.
• 8+ years of experience identifying and exploiting security vulnerabilities across cloud (Azure, AWS, GCP), identity (Entra ID / Active Directory), Windows and Linux endpoints, network, and hardware.
• Experience designing multi-agent or autonomous systems using large language models - orchestration frameworks, tool use, agent evaluation, and safety guardrails - applied to offensive security.
• 6+ years of experience with coding or scripting in languages such as Python, C#, C++, Go, PowerShell, .NET, Rust, or other comparable programming languages, including building and maintaining offensive tooling.
• Experience in customer-facing or consulting roles delivering red team results to executive audiences; ability to move fluently between deep technical detail and business impact.
• Blue team, detection engineering, or incident response experience - you understand how defenders think and can help them get better.
• Familiarity with MITRE ATT&CK, threat-informed defense, and regulated red team frameworks (e.g., TIBER-EU, CBEST, DORA).
• Recognized contributions to the security community: research, open-source tooling, conference talks, or CVEs.

Penetration Testing IC6 - The typical base pay range for this role across the U.S. is USD $165,600 - $296,400 per year. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $220,800 - $331,200 per year.

The Cloud & AI organization accelerates Microsoft’s mission to ensure that our company and industry is securing digital technology platforms, devices, and clouds in our customers’ heterogeneous environments, as well as ensuring the security of our own internal estate. Our culture is centered on embracing a growth mindset, a theme of inspiring excellence, and encouraging teams and leaders to bring their best each day. In doing so, we create life-changing innovations that impact billions of lives around the world.

Are you passionate about emulating the world’s most determined adversaries - and about teaching machines to do it alongside you? Join the Microsoft Red Team (MRT) organization, where we emulate real-world advanced persistent threats to ensure Microsoft, and the customers who depend on us, are prepared to face and respond to any adversary.

CyberShield is the MRT program that extends our red team capability beyond Microsoft’s own estate to select external customers. Our mandate is to shift red teaming from point-in-time, human-led engagements to a software-driven, continuous model powered by agentic, AI-driven red teaming. CyberShield operators work across Microsoft’s own environment and customer environments spanning cloud, identity, network, endpoint, hardware, and operational security domains, and partner closely with Microsoft’s adversary hunting organization to present a unified front to the customers we defend together.

We are looking for a Principal Security Engineer to serve as a principal-level operator on CyberShield engagements. You will plan and execute full-scope adversary emulation operations end-to-end, and - critically - you will drive agentic, AI-driven red team operations: designing, directing, and supervising autonomous and semi-autonomous agents that discover, chain, and exploit weaknesses at a scale and cadence no human-only team can match. You will be a forward-deployed technical authority in front of customer security leaders, a trusted peer to senior engineers across MRT, and a force multiplier who raises the technical bar for every operator and agent on the team.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.

In alignment with our Microsoft values, we are committed to cultivating an inclusive work environment for all employees to positively impact our culture every day.