Penetration Testing Engineer

McKesson is an impact-driven, Fortune 10 company that touches virtually every aspect of healthcare. We are known for delivering insights, products, and services that make quality care more accessible and affordable. Here, we focus on the health, happiness, and well-being of you and those we serve – we care. What you do at McKesson matters. We foster a culture where you can grow, make an impact, and are empowered to bring new ideas. Together, we thrive as we shape the future of health for patients, our communities, and our people. If you want to be part of tomorrow’s health today, we want to hear from you. The McKesson Pentest Team is seeking a Penetration Testing Engineer to help support and scale McKesson's Continuous Adversarial Testing (CART) program and strengthen the security posture of our enterprise application ecosystem. This role provides technical support for offensive security programs, focusing on AI-enabled security testing, web application penetration testing, cloud security assessments, vulnerability validation, and adversarial testing across large-scale application portfolios. The individual in this role will partner with a pentest lead, engineering, product, cloud, and security teams to identify complex attack paths, validate threats, and drive remediation efforts that reduce business risk. The position will play a key role in executing autonomous security testing capabilities, integrating CART outputs into security operations, and advancing McKesson's offensive security assessments. This role will also help shape the future direction of AI-assisted security testing, automation, and modern offensive security methodologies across the enterprise. This is a hands-on technical role for someone who can support the development of a new security program while also performing advanced technical testing, validating AI-generated findings, solving operational challenges, and supporting the long-term direction of McKesson’s offensive security capabilities.

What You'll Do Work closely with a Lead Pentest Engineer to Implement McKesson’s Continuous Adversarial Testing program across large application portfolios. Support and help shape the first iteration of the CART operating model. Execute and refine repeatable onboarding processes covering application context, test accounts, authentication, authorization roles, test data, rate limits, WAF coordination, exclusions, maintenance windows, and emergency stop procedures. Perform human-in-the-loop reviewing, reproducing, validating, prioritizing, and communicating findings generated by autonomous testing platforms. Support the execution of continuous AI assisted penetration tests across high-priority enterprise web applications, including application onboarding, test orchestration, execution oversight, findings validation, and remediation coordination. Implement integrations between CART platforms and vulnerability management, engineering, reporting, and remediation workflows. Conduct AI-enabled web application, API, and cloud security assessments across enterprise environments. Perform penetration testing, adversarial assessments, and vulnerability validation activities against internally developed and third-party applications. Evaluate emerging autonomous security testing capabilities and recommend changes to CART strategy, tooling, and service delivery. Contribute to program documentation including; playbooks, runbooks, technical standards, training materials. Leverage automation and AI-assisted security tooling to scale testing coverage and improve assessment efficiency. Identify and validate complex attack paths involving authentication weaknesses, authorization flaws, business logic vulnerabilities, and multi-stage exploitation scenarios. Evaluate REST APIs, GraphQL APIs, cloud-native architectures, and modern authentication technologies. Partner with engineering teams to explain findings, prioritize remediation efforts, and validate fixes through retesting. Develop and maintain testing methodologies, automation workflows, and security assessment procedures. Contribute to incident investigations, threat modeling activities, and continuous security improvement initiatives. Basic

Requirements 4+ years of cybersecurity, application security, penetration testing, offensive security, or related experience. Bachelor's degree or equivalent combination of education and experience. Experience performing web application and API penetration testing. Experience validating security vulnerabilities, assessing exploitability, and distinguishing actionable findings from false positives. Experience assessing enterprise applications utilizing REST APIs, GraphQL APIs, authentication systems, and cloud-native technologies. Working knowledge of AWS, Azure, or Google Cloud Platform (GCP) security concepts. Experience documenting technical findings and communicating remediation guidance to engineering teams. Hands-on experience with Burp Suite Professional, Nuclei, Nmap, Metasploit, Postman, and Kali Linux tools. Preferred Skills/Experience Experience leveraging AI-assisted security tools and security automation platforms. Experience implementing, operating, or scaling continuous security testing, attack simulation, breach and attack simulation, or automated offensive security capabilities. Experience evaluating, validating, and triaging findings from automated or AI-assisted security testing platforms. Experience assessing AI-enabled applications, agent-based systems, LLM integrations, or AI security risks. Familiarity with DevSecOps, CI/CD security controls, and secure software development practices. Knowledge of OWASP Top 10, API Security Top 10, threat modeling, and secure design principles. Experience conducting red team, adversarial simulation, or attack path validation exercises. Knowledge of cloud security architecture and containerized environments. Experience performing cloud security assessments in AWS, Azure, and GCP environments. Experience cr