Company lists · Data refreshed September 2026

Top 25 Penetration testing staffing companies based in the Netherlands

RevenueBase identified 105 penetration testing staffing companies headquartered in the Netherlands as of September 2026 and tracks 800 professional contacts across them, including 210 with verified work emails. Amsterdam is the largest hub.

This list covers penetration testing staffing companies headquartered in the Netherlands, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
105Companies
800Contacts tracked
210Verified emails
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The 25 largest penetration testing staffing companies based in the Netherlands

Ranked by team size
Top 25 of 105 penetration testing staffing companies based in the Netherlands, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to penetration testing staffing companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidence3447gg, NetherlandsHQ checked Sep 29, 202611-5037 contacts →

Indirect evidence

“Surelock IT Security Services helpt organisatie inzicht te krijgen in de IT-kwetsbaarheden van hun organisatie.”

Source: RevenueBase Database · checked Sep 29, 2026
2Strong evidenceAmsterdam, NetherlandsHQ checked Sep 29, 202611-5034 contacts →

Strong evidence

“Penetration Testing | Agile Security Testing | Red Teaming Securify is a cybersecurity company with a team of professional and passionate ethical hackers, secure coding experts…”

Source: RevenueBase Database · checked Sep 29, 2026
3Indirect evidenceRijswijk, NetherlandsHQ checked Sep 29, 202611-5029 contacts →

Indirect evidence

“Het succes van organisaties hangt steeds meer af van de prestaties van de IT-afdeling.”

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceDeventer, NetherlandsHQ checked Sep 29, 202651-20027 contacts →

Indirect evidence

“Rechtstreeks uw specialisten regelen bij de grootste cybersecurity-community van Nederland?”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect evidenceDelft, NetherlandsHQ checked Sep 29, 202611-5025 contacts →

Indirect evidence

“LBVD is een Delfts onderzoeks- en adviesbureau gespecialiseerd in digitale veiligheid, cybersecurity (ICT-security) en informatiebeveiliging, met 20+ jaar ervaring.”

Source: RevenueBase Database · checked Sep 29, 2026
6Indirect evidenceRotterdam, NetherlandsHQ checked Sep 29, 202611-5023 contacts →

Indirect evidence

“ThreadStone is uw toonaangevende specialist op het gebied van cybersecurity.”

Source: RevenueBase Database · checked Sep 29, 2026
7Strong evidenceLeiden, NetherlandsHQ checked Sep 29, 202611-5018 contacts →

Strong evidence

“DongIT is an independent web security and web development company specializing in penetration testing, secure software development, and custom-built web applications.”

Source: RevenueBase Database · checked Sep 29, 2026
8Partial evidenceLeiderdorp, NetherlandsHQ checked Sep 29, 202611-5016 contacts →

Partial evidence

“REQON is gespecialiseerd in het uitvoeren van technische beveiligingsonderzoeken in de vorm van (maatwerk) penetratietesten en exposure onderzoeken.”

Source: RevenueBase Database · checked Sep 29, 2026
9Indirect evidenceAlmere, NetherlandsHQ checked Sep 29, 202611-5011 contacts →

Indirect evidence

“Even when your security is well underpinned, it remains important to remain alert to possible vulnerabilities, to the system's alerting and response capabilities and to the…”

Source: RevenueBase Database · checked Sep 29, 2026
10Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 29, 20261-1011 contacts →

Indirect evidence

“Sekurno is a cybersecurity company that provides security services beyond mere compliance.”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceBleskensgraaf, NetherlandsHQ checked Sep 29, 20261-1010 contacts →

Indirect evidence

“Cyber Cloud is een jong, ambitieus en innovatief bedrijf, gespecialiseerd in het uitvoeren van technische testen met als doel kwetsbaarheden in uw (web/mobiele)applicaties…”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 29, 202611-5010 contacts →

Indirect evidence

“We connect organizations with proven expertise.”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceBreda, NetherlandsHQ checked Sep 29, 20261-109 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceUtrecht, NetherlandsHQ checked Sep 29, 202611-509 contacts →

Indirect evidence

“Onvio is dé specialist in het uitvoeren van Pentesten.”

Source: RevenueBase Database · checked Sep 29, 2026
15Indirect evidenceIjsselstein, NetherlandsHQ checked Sep 29, 202651-2009 contacts →

Indirect evidence

“Qualityhouse heet sinds 1 januari 2014 Centric.”

Source: RevenueBase Database · checked Sep 29, 2026
16Partial evidenceAmsterdam, NetherlandsHQ checked Sep 29, 20261-108 contacts →

Partial evidence

“Als onderdeel van de Stratis Groep levert nSEC/Resilience hoogwaardige diensten op het gebied van Penetratietesten, Security Awareness, Red Teaming, Cloud Security Audits en…”

Source: RevenueBase Database · checked Sep 29, 2026
17Indirect evidenceDen Haag, NetherlandsHQ checked Sep 29, 20261-108 contacts →

Indirect evidence

“RedVenture is gespecialiseerd in het bemiddelen van tijdelijk en vast IT-personeel.”

Source: RevenueBase Database · checked Sep 29, 2026
18Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 29, 202611-508 contacts →

Indirect evidence

“WebSec is an all-in-one security company.”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect evidenceLeiden, NetherlandsHQ checked Sep 29, 202611-507 contacts →

Indirect evidence

“HackDefense is sinds 2023 onderdeel van Securance.”

Source: RevenueBase Database · checked Sep 29, 2026
20Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 29, 20261-106 contacts →

Indirect evidence

“MVPeople Group, Cybersecurity Recruitment Specialists Your people aren't just your most valuable asset.”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceAlmere, NetherlandsHQ checked Sep 29, 202611-506 contacts →

Partial evidence

“Rootsec brengt aan de hand van Penetratietesten de risico’s en kwetsbaarheden binnen uw IT-omgeving in kaart.”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 29, 202611-506 contacts →

Indirect evidence

“Is uw infrastructuur bestand tegen cybercrime?”

Source: RevenueBase Database · checked Sep 29, 2026
23Strong evidenceThe Hague, NetherlandsHQ checked Sep 29, 202611-506 contacts →

Strong evidence

“Blueprint Security specialises in manual penetration testing and multiple IT security certification consultancy.”

Source: RevenueBase Database · checked Sep 29, 2026
24Indirect evidenceHj, NetherlandsHQ checked Sep 29, 202611-505 contacts →

Indirect evidence

“Het internet ontvouwt zich sinds de jaren 90 in razendsnel tempo.”

Source: RevenueBase Database · checked Sep 29, 2026
25Indirect evidenceWeert, NetherlandsHQ checked Sep 29, 20261-105 contacts →

Indirect evidence

“Shellback is an enthusiastic and dedicated team of security specialists based in Weert.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 105 penetration testing staffing companies based in the Netherlands

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Penetration testing staffing companies based in the Netherlands at a glance

As of Sep 29, 2026
26.2%Verified-email coverage
7.6Average contacts per company
1-10Median size (employees)
17.1%Largest-city concentration · Amsterdam
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
73
11-50
27
51-200
4
201-500
1

Email recency for this list is measured worldwide rather than for Netherlands, so it is reported there. Company counts and contact totals on this page are exact for Netherlands, over 105 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among penetration testing staffing companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the Netherlands whose own description of what they do matches “penetration testing staffing companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names penetration testing staffing companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among penetration testing staffing companies, and records with no verified work email. Companies headquartered outside Netherlands are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 210 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 29, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names penetration testing staffing companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many penetration testing staffing companies are there based in the Netherlands?

RevenueBase identified 105 penetration testing staffing companies headquartered in the Netherlands as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Surelock IT Security Services, headquartered in Woerden, tops this list with the largest team on record.

Which city has the most penetration testing staffing companies?

Amsterdam leads with 18 headquartered companies, followed by Rotterdam (6) and Groningen (4).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 210 verified decision-maker contacts tracked across these 105 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 29, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.