Company lists · Data refreshed September 2026

Top 24 Defense cybersecurity companies based in New York, United States

Name: Defense cybersecurity companies based in New York, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 10, 2026 78 companies tracked

RevenueBase identified 78 defense cybersecurity companies headquartered in New York, United States as of September 2026 and tracks 1,085 professional contacts across them, including 415 with verified work emails and 302 with mobile numbers. Washington is the largest hub.

This list covers defense cybersecurity companies headquartered in New York, United States, 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 10, 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 10, 2026 86% judged on-target in blind review

78Companies

1,085Contacts tracked

415Verified emails

302Mobile numbers

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The 24 largest defense cybersecurity companies based in New York, United States

Ranked by team size

Top 24 of 78 defense cybersecurity companies based in New York, United States, ranked by team size, largest first. Data refreshed Sep 10, 2026. RevenueBase Smart Search rates how each company's information relates to defense cybersecurity 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Harbor IT	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	201-500	163 contacts →
	Partial evidence “Harbor IT helps organizations secure, operate, and scale through integrated IT, cybersecurity, AI, and cloud services.” Source: RevenueBase Database · checked Sep 10, 2026
2	Morphisec	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	104 contacts →
	Indirect evidence “We empower organizations with resilient, self-healing capabilities that prevent and neutralize even the most advanced cyber threats.” Source: RevenueBase Database · checked Sep 10, 2026
3	Trail Of Bits	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	94 contacts →
	Indirect evidence “Since 2012, Trail of Bits has been the premier place for security experts to boldly advance security and address technology’s newest and most challenging risks.” Source: RevenueBase Database · checked Sep 10, 2026
4	Nopalcyber	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	76 contacts →
	Partial evidence “NopalCyber makes cybersecurity manageable, affordable, reliable, and powerful for companies that need to be resilient and compliant.” Source: RevenueBase Database · checked Sep 10, 2026
5	Eretmis INC	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	n/a	66 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 10, 2026
6	Revelsi	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	65 contacts →
	Partial evidence “RevelSI is a global cybersecurity, AI, software, and infrastructure services organization.” Source: RevenueBase Database · checked Sep 10, 2026
7	Nsknox	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	11-50	57 contacts →
	Partial evidence “nsKnox is a cybersecurity company focused on Corporate Payment Security, founded and led by Alon Cohen, Founder & former CEO of CyberArk (NASDAQ: CYBR).” Source: RevenueBase Database · checked Sep 10, 2026
8	Ciphertechs A Cybermaxx Company	Partial evidence	New York, United StatesHQ checked Sep 10, 2026	51-200	28 contacts →
	Partial evidence “CipherTechs is now part of CyberMaxx, a tech-enabled cybersecurity service provider.” Source: RevenueBase Database · checked Sep 10, 2026
9	Unit 221b	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	11-50	16 contacts →
	Partial evidence “Unit 221B is a threat disruption company delivering actionable threat intelligence and cybersecurity solutions that enable enterprises, law enforcement, and government agencies to…” Source: RevenueBase Database · checked Sep 10, 2026
10	Cyberconvoy	Indirect evidence	New York, United StatesHQ checked Sep 10, 2026	11-50	12 contacts →
	Indirect evidence “We’re the nemesis of evil hackers attempting to take control of your system so they can extort money.” Source: RevenueBase Database · checked Sep 10, 2026
11	Resonance Security	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	11-50	9 contacts →
	Partial evidence “Resonance Security offers full spectrum cybersecurity aggregation software for institutions and individuals that makes protecting against any cybersecurity threat effortless no…” Source: RevenueBase Database · checked Sep 10, 2026
12	Sayfer Cyber Security	Indirect evidence	New York, United StatesHQ checked Sep 10, 2026	11-50	8 contacts →
	Indirect evidence “Sayfer, where people and technology meet to overcome web3 and blockchain challenges.” Source: RevenueBase Database · checked Sep 10, 2026
13	Holistic Cyber Holisticyber	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	8 contacts →
	Partial evidence “HolistiCyber’s mission is to assist corporations in defending themselves from the new phase of evolution in Cyber threats - not only in volume, but in the level of sophistication.” Source: RevenueBase Database · checked Sep 10, 2026
14	MITG	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	7 contacts →
	Indirect evidence “MITG exists because most businesses don't need another security vendor.” Source: RevenueBase Database · checked Sep 10, 2026
15	Firedome	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	11-50	7 contacts →
	Partial evidence “Firedome, a cybersecurity trailblazer, specializes in detection and response solutions for networks and IoT devices tailored for enterprise settings.” Source: RevenueBase Database · checked Sep 10, 2026
16	Kopidion	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	5 contacts →
	Indirect evidence “Kopidion consists of highly qualified cyber operations and information security professionals.” Source: RevenueBase Database · checked Sep 10, 2026
17	Citanex	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	11-50	4 contacts →
	Indirect evidence “Citanex was founded by a former US Secret Service Electronic Crimes Agent with advisory credentials from Harvard, MIT, and the Department of Justice.” Source: RevenueBase Database · checked Sep 10, 2026
18	Velstadt Cybersecurity	Strong evidence	New York, United StatesHQ checked Sep 10, 2026	11-50	4 contacts →
	Strong evidence “Velstadt is a cybersecurity provider focused on delivering both offensive and defensive security services.” Source: RevenueBase Database · checked Sep 10, 2026
19	Bytium	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	4 contacts →
	Partial evidence “Bytium LLC is a U.S-registered cybersecurity and IT solutions firm dedicated to helping organizations protect their information assets and maintain operational resilience.” Source: RevenueBase Database · checked Sep 10, 2026
20	Secreliant	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	3 contacts →
	Partial evidence “SecReliant is managed by a seasoned team – with backgrounds in cybersecurity, technology, blockchain enabled technology, and service in the armed forces – that is passionate…” Source: RevenueBase Database · checked Sep 10, 2026
21	D-Riskcyber LLC	Partial evidence	New York, United StatesHQ checked Sep 10, 2026	51-200	2 contacts →
	Partial evidence “d-RiskCyber is a global consulting firm headquartered in New York City and specializing in cybersecurity-by-design and data-protection-by-design solutions.” Source: RevenueBase Database · checked Sep 10, 2026
22	Aniza Corp	Indirect evidence	New York, NY, United StatesHQ checked Sep 10, 2026	51-200	1 contacts →
	Indirect evidence “Technology Transformation Public / Private / Hybrid Cloud Architecture IAM / CIAM Cyber Maturity Assessment Cyber Strategy and Target Operating Model Development Security Risk…” Source: RevenueBase Database · checked Sep 10, 2026
23	Opsai LLC	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	1 contacts →
	Partial evidence “Cybersecurity models of the past no longer work well, and the best practices of software design and running of complex systems are used more today by cybercriminals than by…” Source: RevenueBase Database · checked Sep 10, 2026
24	Cyvergence	Partial evidence	New York, NY, United StatesHQ checked Sep 10, 2026	1-10	1 contacts →
	Partial evidence “At Cyvergence, our mission is to empower organizations by delivering state of the art cybersecurity products and services that fortify your digital ecosystem.” Source: RevenueBase Database · checked Sep 10, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: defense cybersecurity companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names defense cybersecurity companies.
Partial evidence: Its own public description names part of defense cybersecurity companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name defense cybersecurity companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 24 of 78 defense cybersecurity companies based in New York, United States

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Defense cybersecurity companies based in New York, United States at a glance

As of Sep 10, 2026

38.2%Verified-email coverage

27.8%Mobile-number coverage

13.9Average contacts per company

1-10Median size (employees)

116.7%Largest-city concentration · Washington

Sep 10, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

1,001-5,000

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 12.0d

3790–30

3531–60

061–90

090–180

1180+

Company record updated

Median 54.0d

00–30

60531–60

32361–90

9690–180

61180+

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 defense cybersecurity 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 New York, United States whose own description of what they do matches “defense cybersecurity 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 defense cybersecurity 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 defense cybersecurity companies, and records with no verified work email. Companies headquartered outside New York 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, 415 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 10, 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.

Defense cybersecurity companies by metro in the United States

Defense cybersecurity companies in Washington91
Defense cybersecurity companies in New York84
Defense cybersecurity companies in Houston58
Defense cybersecurity companies in Austin57
Defense cybersecurity companies in Columbia56
Defense cybersecurity companies in Arlington56
Defense cybersecurity companies in Miami54

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 defense cybersecurity 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 defense cybersecurity companies are there based in New York, United States?

RevenueBase identified 78 defense cybersecurity companies headquartered in New York, United States 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?

Harbor IT, headquartered in New York, tops this list with the largest team on record.

Which city has the most defense cybersecurity companies?

Washington leads with 91 headquartered companies, followed by New York (84) and Houston (58).

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 415 verified decision-maker contacts tracked across these 78 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 10, 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.