Company lists · Data refreshed September 2026

Top 25 Network security audit companies based in the Netherlands

RevenueBase identified 119 network security audit companies headquartered in the Netherlands as of September 2026 and tracks 754 professional contacts across them, including 183 with verified work emails. Amsterdam is the largest hub.

This list covers network security audit 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 21, 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 21, 2026 86% judged on-target in blind review
119Companies
754Contacts tracked
183Verified emails
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The 25 largest network security audit companies based in the Netherlands

Ranked by team size
Top 25 of 119 network security audit companies based in the Netherlands, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to network security audit 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
1Partial evidence3447gg, NetherlandsHQ checked Sep 21, 202611-5037 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
2Partial evidenceDelft, NetherlandsHQ checked Sep 21, 202611-5025 contacts →

Partial 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 21, 2026
3Indirect evidenceRotterdam, NetherlandsHQ checked Sep 21, 202611-5023 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
4Partial evidenceLeiden, NetherlandsHQ checked Sep 21, 202611-5018 contacts →

Partial 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 21, 2026
5Indirect evidenceLeiderdorp, NetherlandsHQ checked Sep 21, 202611-5016 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
6Indirect evidenceUtrecht, NetherlandsHQ checked Sep 21, 202611-5015 contacts →

Indirect evidence

“At Cyber Seals, we believe in a digital world where you can work, innovate, and grow securely.”

Source: RevenueBase Database · checked Sep 21, 2026
7Partial evidenceAlkmaar, NetherlandsHQ checked Sep 21, 20261-1012 contacts →

Partial evidence

“Specialists from Sirius Security have all the skills to help enterprise organisations to secure their IT environment.”

Source: RevenueBase Database · checked Sep 21, 2026
8Partial evidenceAlmere, NetherlandsHQ checked Sep 21, 202611-5011 contacts →

Partial 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 21, 2026
9Partial evidenceAmsterdam, NetherlandsHQ checked Sep 21, 20261-1011 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceBleskensgraaf, NetherlandsHQ checked Sep 21, 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 21, 2026
11Indirect evidenceRoelofarendsveen, NetherlandsHQ checked Sep 21, 20261-1010 contacts →

Indirect evidence

“Hoe vatbaar is jouw organisatie voor hacks?”

Source: RevenueBase Database · checked Sep 21, 2026
12Partial evidenceAmsterdam, NetherlandsHQ checked Sep 21, 20261-109 contacts →

Partial evidence

“Cert2Connect BV is the go-to party in the field of advanced digital security solutions, security services and cyber security.”

Source: RevenueBase Database · checked Sep 21, 2026
13Indirect evidenceUtrecht, NetherlandsHQ checked Sep 21, 202611-509 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
14Indirect evidenceZoetermeer, NetherlandsHQ checked Sep 21, 20261-109 contacts →

Indirect evidence

“Zoeken naar verbinding, en het bieden van totaaloplossingen, dat is waar wij continu mee bezig zijn.”

Source: RevenueBase Database · checked Sep 21, 2026
15Indirect evidenceZevenbergen, NetherlandsHQ checked Sep 21, 202611-507 contacts →

Indirect evidence

“With Attic, the hacking experts from Zolder provide organizations with high-end cybersecurity operations.”

Source: RevenueBase Database · checked Sep 21, 2026
16Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 21, 20261-105 contacts →

Indirect evidence

“The Catcher24 Scanner identifies vulnerabilities so you will quickly know when you are at risk.”

Source: RevenueBase Database · checked Sep 21, 2026
17Indirect evidenceZaandam, NetherlandsHQ checked Sep 21, 20261-105 contacts →

Indirect evidence

“Netwerkbeveiliging is nog nooit zo uitdagend geweest.”

Source: RevenueBase Database · checked Sep 21, 2026
18Partial evidenceWeert, NetherlandsHQ checked Sep 21, 20261-105 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
19Partial evidenceUtrecht, NetherlandsHQ checked Sep 21, 20261-104 contacts →

Partial evidence

“ThreatLabs specializes in security assessments providing valuable insights in vulnerabilities and weaknesses as well as actionable advise to increase the security posture of IT…”

Source: RevenueBase Database · checked Sep 21, 2026
20Partial evidenceAmsterdam, NetherlandsHQ checked Sep 21, 20261-104 contacts →

Partial evidence

“Over BSM Business Security Management BV BSM biedt sinds 2004 gespecialiseerde cybersecurity- en informatiebeveiligingsdiensten aan voor onder andere MKB, scholen, stichtingen…”

Source: RevenueBase Database · checked Sep 21, 2026
21Indirect evidenceZeewolde, NetherlandsHQ checked Sep 21, 20261-104 contacts →

Indirect evidence

“Stel je voor, ergens in het digitale universum waarin we leven, zijn er sluwe hackers die de boel willen verstoren.”

Source: RevenueBase Database · checked Sep 21, 2026
22Indirect evidenceSittard, NetherlandsHQ checked Sep 21, 20261-104 contacts →

Indirect evidence

“Be s(ec)ure!”

Source: RevenueBase Database · checked Sep 21, 2026
23Indirect evidenceVleuten, NetherlandsHQ checked Sep 21, 20261-104 contacts →

Indirect evidence

“At Secuza, we enable our customers in improving their business operations by leveraging our industry-wide experience, expertise in cutting-edge technology and an extensive…”

Source: RevenueBase Database · checked Sep 21, 2026
24Indirect evidenceArnhem, NetherlandsHQ checked Sep 21, 202611-503 contacts →

Indirect evidence

“Het is voor onze economie en samenleving essenstiel dat digitale infrastructuren betrouwbaar en beschikbaar zijn.”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 21, 20261-103 contacts →

Indirect evidence

“Bij Socured geloven we niet in vendor-gedreven advies of losse oplossingen.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 119 network security audit companies based in the Netherlands

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Network security audit companies based in the Netherlands at a glance

As of Sep 21, 2026
24.3%Verified-email coverage
6.3Average contacts per company
1-10Median size (employees)
11.8%Largest-city concentration · Amsterdam
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
92
11-50
22
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 119 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 network security audit 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 “network security audit 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 network security audit 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 network security audit 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, 183 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 21, 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 network security audit 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 network security audit companies are there based in the Netherlands?

RevenueBase identified 119 network security audit 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 network security audit companies?

Amsterdam leads with 14 headquartered companies, followed by Rotterdam (4) and Amersfoort (3).

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 183 verified decision-maker contacts tracked across these 119 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 21, 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.