Company lists · Data refreshed September 2026

Top 15 Operational technology security services based in Greece

RevenueBase identified 32 operational technology security services headquartered in Greece as of September 2026 and tracks 511 professional contacts across them, including 222 with verified work emails. Athens is the largest hub.

This list covers operational technology security services headquartered in Greece, 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
32Companies
511Contacts tracked
222Verified emails
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The 15 largest operational technology security services based in Greece

Ranked by team size
Top 15 of 32 operational technology security services based in Greece, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to operational technology security services: 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 evidenceAthens, GreeceHQ checked Sep 29, 202651-200194 contacts →

Indirect evidence

“CENSUS is a cybersecurity engineering powerhouse.”

Source: RevenueBase Database · checked Sep 29, 2026
2Partial evidenceAthens, GreeceHQ checked Sep 29, 202651-200159 contacts →

Partial evidence

“ADACOM, a Byte subsidiary, enables security online for Financial Institutions, Telecom Operators, Governments and Large Organizations, in more than 30 countries in EMEA.”

Source: RevenueBase Database · checked Sep 29, 2026
3Indirect evidenceMetamorfosi, GreeceHQ checked Sep 29, 202611-5025 contacts →

Indirect evidence

“Our company's structure is based on a modern and flexible model ensuring adaptation in running developments but also in continuous requirements and needs of our clients.”

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceAthens, GreeceHQ checked Sep 29, 202611-5020 contacts →

Indirect evidence

“At ThreatScene, we are committed to setting new standards in cybersecurity by delivering exceptional, high-quality services designed to protect your most valuable digital assets.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect evidenceKhalándrion, GreeceHQ checked Sep 29, 202611-5017 contacts →

Indirect evidence

“Alphabit is an expert Cybersecurity services provider.”

Source: RevenueBase Database · checked Sep 29, 2026
6Partial evidenceAgios Dimitrios, GreeceHQ checked Sep 29, 202611-5012 contacts →

Partial evidence

“CyberNoesis was established in 2015 by cyber security specialists with extensive experience in enterprise, industrial and telecommunications sectors.”

Source: RevenueBase Database · checked Sep 29, 2026
7Partial evidenceAthens, GreeceHQ checked Sep 29, 202611-507 contacts →

Partial evidence

“Cygnus Technologies is a leading Greece-based provider of managed IT Cybersecurity services for the shipping industry.”

Source: RevenueBase Database · checked Sep 29, 2026
8Indirect evidenceNea Smyrni, GreeceHQ checked Sep 29, 20261-107 contacts →

Indirect evidence

“Η Cysoft Σύμβουλοι Πληροφορικής ΕΠΕ ιδρύθηκε το 1998 για να διαθέσει στην Ελληνική Αγορά επιλεγμένα προϊόντα και λύσεις ασφάλειας πληροφορικής.”

Source: RevenueBase Database · checked Sep 29, 2026
9Partial evidenceKoropi, GreeceHQ checked Sep 29, 202611-506 contacts →

Partial evidence

“Logisek is a leading Cyber Security and IT services firm, founded in Greece in 2008 and expanded to Romania in 2019.”

Source: RevenueBase Database · checked Sep 29, 2026
10Partial evidenceAthens, GreeceHQ checked Sep 29, 202611-505 contacts →

Partial evidence

“Started in is now one of the leading companies in managed security services.”

Source: RevenueBase Database · checked Sep 29, 2026
11Partial evidenceChalandri, GreeceHQ checked Sep 29, 20261-104 contacts →

Partial evidence

“At CyberOne we select and integrate the most advanced IT security solutions to address the evolving needs of corporate customers who must protect their information repositories…”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidencePireas, GreeceHQ checked Sep 29, 20261-104 contacts →

Indirect evidence

“f society was founded in 2017 in Greece during the economic crisis, breaking the brain drain rule.”

Source: RevenueBase Database · checked Sep 29, 2026
13Partial evidenceAthens, GreeceHQ checked Sep 29, 20261-102 contacts →

Partial evidence

“We are a cyber security firm based in Greece operating in the EMEA region.”

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceAmaroúsion, GreeceHQ checked Sep 29, 202611-502 contacts →

Indirect evidence

“Nisos Advisors was established in 2017 by a team of partners with extensive field experience each with over twenty years of line management and consultancy practice.”

Source: RevenueBase Database · checked Sep 29, 2026
15Partial evidenceThessaloniki, GreeceHQ checked Sep 29, 20261-101 contacts →

Partial evidence

“At ST Consultant our mission is to empower our clients with the knowledge, strategies, and technologies needed to protect their assets, people, and information.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 15 of 32 operational technology security services based in Greece

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Operational technology security services based in Greece at a glance

As of Sep 29, 2026
43.4%Verified-email coverage
16.0Average contacts per company
1-10Median size (employees)
43.8%Largest-city concentration · Athens
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
20
11-50
10
51-200
2

Email recency for this list is measured worldwide rather than for Greece, so it is reported there. Company counts and contact totals on this page are exact for Greece, over 32 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 operational technology security services, 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 Greece whose own description of what they do matches “operational technology security services”. 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 operational technology security services), 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 operational technology security services, and records with no verified work email. Companies headquartered outside Greece 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, 222 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 operational technology security services, 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 operational technology security services are there based in Greece?

RevenueBase identified 32 operational technology security services headquartered in Greece 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?

Census, headquartered in Greece, tops this list with the largest team on record.

Which city has the most operational technology security services?

Athens leads with 14 headquartered companies, followed by Filothei Psychiko (1) and Kallithea (1).

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 222 verified decision-maker contacts tracked across these 32 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.