Salary: £30,000 - 60,000 per year Requirements: 4 years' experience in infrastructure penetration testing Deep understanding of Active Directory (AD) based attacks, lateral movement, and privilege escalation Comfort operating in production environments with limited runbooks or documentation Strong Windows and Linux command-line skills Ability to work with legacy systems and navigate environments with technical debt Desirable skills & qualifications: Python scripting or coding skills (advantageous) Exposure to operational technology (OT) networks and internal infrastructure tooling Relevant certifications such as CREST (CTM, CTL, CSTM), Cyber Scheme Practitioner, or OSCP Responsibilities: Deliver internal infrastructure penetration tests, with an emphasis on Active Directory environments Act as a trusted advisor to clients in a hands-on consulting role Document clear and concise technical reports for both technical and non-technical stakeholders Operate independently in sensitive and sometimes live production environments Contribute to the development of tools, methodology, and internal process improvements Demonstrate initiative in building and adapting testing approaches to fit client environments Technologies: Active Directory Linux Python Security Windows Web More: We are a global innovation and transformation consultancy seeking to grow our elite Digital & Data team. As a Penetration Tester, you will be involved in high-stakes client environments, including defence, critical infrastructure, and national security. This role requires confidence in navigating sensitive networks and the ability to consult directly with clients, delivering clear, actionable insights. We offer a flexible hybrid working model, with approximately two days per week spent in client or office locations, while the majority of the work can be conducted remotely. Our primary base is preferred in London, although other UK locations will be considered based on flexibility. We value a tight-knit, high-performing team environment and are committed to providing competitive salaries and packages, including bonuses, pensions, and private healthcare. To be eligible for this role, candidates must be SC clearable, and current SC clearance is highly desirable. If this sounds like your kind of challenge, we encourage you to reach out today. Don't worry if you don’t think you’re the perfect fit; we are hiring across the security space and would love to discuss options with you. last updated 8 week of 2026