We don't study the threat.
We are the threat, working for you

We are The S-Unit. A team of more than 30 security specialists with over a decade of experience in offensive security, driven by curiosity in everything we do. We look beyond the obvious, challenge assumptions and search for ways in, so you can close off attack paths before real attackers find them.

Where it all began

In 2011, Dirk van Veen and Barry van Kampen met at Hack in the Box Amsterdam. Their shared passion for ethical hacking sparked an idea: to approach security research differently. No standard checklists, tick-box exercises or automated scans, but in-depth technical research driven by creativity and tailored approaches. This led to the creation of The S-Unit, short for the Security Unit, which became an independent company in 2015.

Our roots lie in the ethical hacking community, and they continue to shape our culture today. Curiosity drives us to explore new techniques and uncover vulnerabilities that others overlook. We don’t keep that knowledge to ourselves. We give back to the community through training and events, including our own Capture The Flag competitions.

Since 2018, we have been part of the DSE Group. Today, our team has grown to more than 30 security specialists, working on increasingly large and complex projects for banks, government organisations, software providers and healthcare institutions. But one thing has never changed: our commitment to technical depth, creativity and tailored security research.

What we stand for

Everything we do is built on five core values.

Quality

We set high standards and constantly challenge ourselves to improve. Through technical depth, the right tools and knowledge sharing within our team, we deliver work that makes a real difference to our clients.

Reliability

We do what we promise and stand by our colleagues and clients. You can count on clear agreements, open communication and a consistent, thorough approach.

Honesty

We say what needs to be said, even when it's not what you want to hear. We provide independent advice, communicate our findings transparently and take responsibility for our work.

Passion

We're curious security enthusiasts who love experimenting, exploring new techniques and challenging each other. Our passion for ethical hacking keeps us sharp and helps us uncover vulnerabilities that others miss.

Diversity

You don't have to fit a particular mould to belong here. Our differences make us stronger. We give everyone the freedom to be themselves, grow professionally and contribute their own talents and perspectives.

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The Unit

Our security professionals come from a wide range of backgrounds within the security community, from CTF competitors to former government security specialists. Meet some of the experts behind The S-Unit.

Dirk van Veen

Ethical Hacker & Oprichter

Nick Bruinsma

Directeur innovatie

Bas Cijsouw

Ethical Hacker

Patrick Huisman

CISO

Kevin van Straten

Red Team Lead

More than colleagues

At The S-Unit, we're a team of curious, independent-minded security specialists who constantly challenge each other. We enjoy technical discussions, share our latest discoveries and give each other the freedom to experiment.

The atmosphere is informal, communication is direct and there’s always someone willing to think along with you. Even when you come up with a completely crazy idea. Once a month, we put hacking aside for our team day. It’s a chance to connect, share company updates, take part in inspiring sessions and, most importantly, spend time together.

Our passion for hacking doesn’t stop when the working day ends. You’ll regularly find us at Capture The Flag competitions, security conferences and other initiatives within the hacker community. We don’t just participate; we actively contribute. From Hack Right and PViB to our own Mendix CTF, we believe in sharing knowledge and inspiring the next generation of hackers.

Our network

Mendix

We’ve been testing the Mendix platform and Mendix applications since 2015. This extensive experience forms the foundation of our specialised security training. We also share our expertise through the global Mendix Capture The Flag, which attracted more than 1,500 developers in 2025.

Fortra

As the only reseller and knowledge partner for Fortra’s offensive security portfolio in the Benelux, we provide tools such as Cobalt Strike, Core Impact and Outflank Security Tooling. Because we use these tools ourselves, we advise and support clients based on our own hands-on experience.

Eye Security

Together with Eye Security, we combine continuous threat detection with offensive security expertise. Through targeted penetration testing, we investigate which vulnerabilities attackers could actually exploit.

Cerios

Within Cerios, we combine our Mendix security expertise with Omnext’s automated analysis capabilities. Using The S-Unit Top 10, development teams can identify potential security risks early in the development process.

Passguard

Passguard’s platform gives us insight into credentials and session tokens stolen by infostealers. During penetration tests and red team engagements, we safely test whether these credentials and tokens could actually provide access to systems and sensitive information.

Hack your way in

At The S-Unit, you’ll work on challenging security assessments where no two environments are the same and technical depth is at the heart of everything we do. You’ll have the freedom to follow your curiosity and develop your skills, alongside colleagues who are just as critical and independent-minded as you are.

We don't study the threat. We are the threat, working for you