Penetration Testing Engineer

McKesson•Irving, TX

2d•Hybrid

About The Position

McKesson is seeking a Penetration Testing Engineer to support and scale its Continuous Adversarial Testing (CART) program and enhance the security of its enterprise application ecosystem. This role involves providing technical support for offensive security initiatives, including AI-enabled security testing, web application penetration testing, cloud security assessments, vulnerability validation, and adversarial testing across extensive application portfolios. The engineer will collaborate with a pentest lead, engineering, product, cloud, and security teams to identify complex attack paths, validate threats, and drive risk-reducing remediation efforts. Key responsibilities include executing autonomous security testing, integrating CART outputs into security operations, and advancing offensive security assessments. The position will also contribute to the future of AI-assisted security testing, automation, and modern offensive security methodologies within the enterprise. This is a hands-on technical role requiring the ability to support a new security program, perform advanced technical testing, validate AI-generated findings, resolve operational challenges, and influence the long-term direction of McKesson’s offensive security capabilities.

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.

Nice To Haves

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 creating custom security testing scripts and automation workflows.
Experience developing proof-of-concept exploits and adversary emulation scenarios.
Familiarity with security control validation and compliance frameworks.
Experience mentoring engineers and contributing to security program maturity.
Experience supporting regulated industries such as healthcare, finance, or other highly regulated environments.
Relevant certifications such as OSCP, OSWE, OSWA, OSAI, HTB CWES, HTB CWEE, OSEP, GPEN, GWAPT or equivalent.

Responsibilities

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.