BDO Digital Offensive Senior Security Analyst (LONDON)

Ideas | People | Trust 

We’re BDO. An accountancy and business advisory firm, providing the advice and solutions businesses need to navigate today’s changing world.

Our clients are Britain’s economic engine – ambitious, entrepreneurially-spirited and high growth businesses that fuel the economy - and the owners and management teams that lead them.

We’ll broaden your horizons 

Our Consulting team provide a wide variety of services that deliver value-led advice and outcomes. They have an in-depth knowledge of business, industry sectors and markets and understand the constantly changing risks and opportunities at the heart of our clients affairs. 

The  Digital team within Consulting helps our clients create competitive advantage and uncover new avenues of growth and profitability through digital strategies. Strategies need to be bold, but they also need to deliver near-term results. That’s why we take a practical approach that marries long-term vision with quick wins and measurable ROI milestones. Our vision is to be a fully integrated, business-led, end-to-end technology advisor and integrator helping clients to enable business change through leveraging technology.

We’ll help you succeed

Leading organisations trust us because of the quality of our advice. That quality grows from a thorough understanding of their business, and that understanding comes from working closely with them and building long-lasting relationships.

You’ll be someone who is both comfortable working proactively and managing your own tasks, as well as confident collaborating with others and communicating regularly with senior managers, directors, and BDO’s partners to help businesses effectively. You’ll be encouraged to identify and draw attention to opportunities for enhancing our delivery and providing additional services to organisations we work with.

We are seeking a skilled Offensive Security penetration tester to join our dynamic team. This role involves conducting sophisticated penetration testing and red team engagements across various client systems and applications. You’ll be instrumental in identifying vulnerabilities, enhancing client security postures, and leading initiatives to develop cutting-edge penetration testing methodologies and tools. You’ll have exposure to clients across industries and geographies, staying at the forefront of knowledge of the threat landscape, cyber defence best practices and regulatory expectations.

There will be opportunities to gain experience with web applications and API testing, Wireless assessments, Internal infrastructure tests, Mobile App security, Red and Purple team operations, Physical intrusion testing, hardware analysis, and more.

You’ll be someone with

• Certification in penetration testing such as OSCP (Offensive Security Certified Professional), CTM (Check Team Member), CRT (CREST Registered Tester) and OSWA (Offensive Security Web Attacks). OSEP(OffSec Experience Penetration Tester), CCSAM (CREST Certified Simulated Attack Manager) and CTL (Check Team Leader).

• Offensive security—professional penetration testing, red teaming, bug bounty work, capture-the-flag competitions, or personal research projects.

• Proven ability to deliver impactful client engagements, demonstrating both technical depth and a practical understanding of risk.

• Deep knowledge of network protocols, different services, operating systems, different applications and how to break them.

• Proficiency in tools such as Metasploit, Burp Suite or other proxies such as Caido or Zap, Nessus, CobaltStrike or other C2 frameworks

• Excellent problem-solving skills and a passion for ethical hacking

• Experience coding and scripting custom tools in Python, Bash, PowerShell.

Be yourself

It's at the core of the company's and team's vision. You’ll be able to truly be yourself; we’ll recognise and value you for who you are and celebrate and reward your contributions to the business. We’re committed to agile working, and we offer every colleague the opportunity to work in ways that suits them, their teams, and the tasks at hand.

At BDO, we’re committed to helping you achieve your personal and professional goals. We provide structured development frameworks, resources, and mentorship to support your growth—whether you're looking to deepen a specific skillset or broaden your expertise across domains.

We’ll align your client engagements with your learning objectives, giving you the chance to apply new skills, explore areas of interest, and gain practical experience. You won’t be navigating this alone—our team culture emphasizes peer support, collaboration, and knowledge sharing on every project.

We’re in it together

Mutual support and respect are one of BDO’s core values and we’re proud of our distinctive, people-centred culture. From informal success conversations to formal mentoring and coaching, we’ll support you at every stage in your career, whatever your personal and professional needs.

Our agile working framework helps us stay connected, bringing teams together where and when it counts so they can share ideas and help one another. At BDO, you’ll always have access to the people and resources you need to do your best work.

We know that collaboration is the key to creating value for the companies we work with and satisfying experiences for our colleagues, so we’ve invested in state-of-the-art collaboration spaces in our offices. BDO’s people represent a wealth of knowledge and expertise, and we’ll encourage you to build your network, work alongside others, and share your skills and experiences. With a range of multidisciplinary events and dedicated resources, you’ll never stop learning at BDO.

We’re looking forward to the future

At BDO, we help entrepreneurial businesses to succeed, fuelling the UK economy. Our success is powered by our people, which is why we’re always finding new ways to invest in you. Across the UK thousands of unique minds continue to come together to help companies we work with to achieve their ambitions.

We’ve got a clear purpose, and we’re confident in our future, because we’re adapting and evolving to build on our strengths, ensuring we continue to find the right combination of global reach, integrity and expertise. We shape the future together with openness and clarity, because we believe in empowering people to think creatively about how we can do things better.

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