Cyber Security Analyst/Penetration Tester in London

Moore Kingston Smith is seeking an experienced Cyber Security Consultant specialising in penetration testing to join our client-facing advisory team. You will join an NCSC-recognised cyber security team within our Risk Advisory practice, supporting a diverse portfolio of clients across multiple sectors. This is a hands-on role focused on delivering penetration tests across web applications, APIs, and internal and external network infrastructure. You will also support Cyber Essentials Plus assessments and wider technical security reviews, including vulnerability assessments, configuration reviews against recognised benchmarks, and cloud security reviews. You will identify and safely validate security weaknesses, explain the associated business risks clearly, and provide practical remediation advice tailored to each client.

Technical delivery will account for at least 70% of the role and will remain the core focus. Depending on your experience, interests and business requirements, there may also be opportunities to contribute to broader cyber security engagements, including cyber maturity assessments, security control reviews, audit readiness activities and security design advisory work. We are looking for a proactive consultant with strong technical fundamentals, sound professional judgement and a genuine interest in helping clients improve their security posture. This role offers the opportunity to deepen your offensive security expertise while contributing to the continued growth of a collaborative and commercially focused cyber security practice.

Key Responsibilities

• Lead and support penetration testing engagements across web applications, APIs, and internal and external network infrastructure.
• Work with clients to define objectives, agree scope and rules of engagement, and plan testing that meets their assurance needs.
• Apply manual and tool-assisted testing techniques aligned with recognised methodologies and frameworks, including the OWASP Web Security Testing Guide, PTES, and MITRE ATT&CK.
• Deliver wider technical security assessments, including vulnerability assessments, cloud security reviews, and build and configuration reviews against CIS Benchmarks and vendor hardening guidance.
• Produce clear, high-quality deliverables and present findings to technical and non-technical stakeholders.
• Apply appropriate risk ratings, explain business impact, and support clients with remediation and retesting.
• Support general advisory engagements such as cyber risk assessments, security control reviews, audit readiness, remediation planning and security design advice.
• Maintain current knowledge of the threat landscape, emerging attack techniques, testing methodologies, and scheme requirements, while contributing to peer review and quality assurance.

Skills, Knowledge and Expertise

• Professional experience delivering client-facing penetration tests across web applications, APIs, and internal or external network infrastructure, independently and/or as part of a team.
• Strong manual testing capability and sound judgement in selecting and using automated tools, with practical experience of Kali Linux, Burp Suite, Nmap, and Qualys or Nessus.
• Familiarity with recognised penetration testing methodologies and frameworks, together with the ability to script or automate tasks using Python, PowerShell, Bash, or a comparable language.
• Good knowledge of modern web architecture, common web and API vulnerabilities, TCP/IP, Windows and Linux security, and Active Directory and Microsoft Entra ID attack paths.
• Experience delivering, or the ability to deliver, wider technical assessments such as vulnerability assessments and configuration reviews against recognised benchmarks such as CIS. Appropriate training will be provided where required.
• Ability to manage engagements within agreed scope, rules of engagement, timescales, budget, and quality standards, while maintaining clear testing evidence and protecting client systems and data.
• Strong verbal communication and stakeholder-management skills, with the ability to explain technical findings, risk, and business impact to technical and non-technical audiences.
• A proactive, client-oriented mindset and a commitment to continuous learning, confident working with clients ranging from SMEs and scale-ups to larger enterprises.
• Experience in additional testing disciplines such as mobile application, wireless or cloud penetration testing, or phishing and social-engineering assessments.
• Experience with public cloud and SaaS platforms such as AWS, Azure, GCP or Microsoft 365, or hands-on security or IT engineering experience such as hardening systems and implementing technical controls.
• An interest in, or experience of, broader advisory work such as cyber risk assessments, security control reviews, audit readiness, or working knowledge of a recognised framework such as ISO/IEC 27001, NIST, or CIS Controls.