Company lists · Data refreshed September 2026

Top 25 Biggest security companies based in Herndon, United States

Name: Biggest security companies based in Herndon, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 43 companies tracked

RevenueBase identified 43 biggest security companies headquartered in Herndon, United States as of September 2026 and tracks 13,728 professional contacts across them, including 3,508 with verified work emails. New York is the largest hub.

This list covers biggest security companies headquartered in Herndon, 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 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

43Companies

13,728Contacts tracked

3,508Verified emails

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The 25 largest biggest security companies based in Herndon, United States

Ranked by team size

Top 25 of 43 biggest security companies based in Herndon, United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to biggest security 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	Mantech	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	5,001-10,000	9,697 contacts →
	Indirect evidence “MANTECH is more than a technology company.” Source: RevenueBase Database · checked Sep 21, 2026
2	Paragon Systems INC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	10001+	1,949 contacts →
	Partial evidence “Paragon Systems employs over 10,500 professionals in specialized operations providing security, fire, investigations, inspections, cybersecurity, risk management, and mission…” Source: RevenueBase Database · checked Sep 21, 2026
3	Omniplex World Services Corporation	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	677 contacts →
	Partial evidence “OMNIPLEX World Services Corporation is a leader and innovator in delivering professional background investigations, intelligence support, and physical security services to…” Source: RevenueBase Database · checked Sep 21, 2026
4	Netcentrics	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	122 contacts →
	Indirect evidence “For 30 years, NetCentrics has excelled as an innovative technology solutions provider for the U.S.” Source: RevenueBase Database · checked Sep 21, 2026
5	Foxhole Technology	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	117 contacts →
	Indirect evidence “Foxhole Technology is a thought-leading technology firm offering a robust suite of cybersecurity, software development, systems engineering, and test & evaluation solutions for…” Source: RevenueBase Database · checked Sep 21, 2026
6	Indigo IT LLC	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	101 contacts →
	Indirect evidence “Founded in 2001, Indigo IT is an award winning information technology consulting and services company.” Source: RevenueBase Database · checked Sep 21, 2026
7	Truestone, LLC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	94 contacts →
	Partial evidence “Truestone provides full lifecycle, business driven technology and information security-oriented services and solutions across the public and private sectors.” Source: RevenueBase Database · checked Sep 21, 2026
8	Integrated Security Technologies, INC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	61 contacts →
	Partial evidence “Integrated Security Technologies designs, integrates, installs and maintains comprehensive solutions for the most complex and important IT, electronic, physical and cyber security…” Source: RevenueBase Database · checked Sep 21, 2026
9	Chameleon Consulting Group LLC	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	59 contacts →
	Indirect evidence “Chameleon Consulting Group, LLC was founded by a small group of professionals with extensive experience in cyber operations, software engineering, data analysis, and physical…” Source: RevenueBase Database · checked Sep 21, 2026
10	AVINT	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	48 contacts →
	Indirect evidence “Your Vision Achieved.” Source: RevenueBase Database · checked Sep 21, 2026
11	Athena Technology Group	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	45 contacts →
	Partial evidence “Cyber Security (Vulnerability Assessments, 24/7 Operations, Hunt Teams, Risk Management, Cyber Response) Program Management (Acquisition, Financial, Technology Insertion) System…” Source: RevenueBase Database · checked Sep 21, 2026
12	Sphinx Solutions INC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	11-50	38 contacts →
	Partial evidence “Sphinx Solutions is an entrepreneurial cyber security company that helps private- and public-sector organizations take advantage of solutions that match today’s security…” Source: RevenueBase Database · checked Sep 21, 2026
13	Network Depot	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	34 contacts →
	Indirect evidence “Network Depot has been serving the DC Metro area since 1991, providing technical support and cybersecurity consulting.” Source: RevenueBase Database · checked Sep 21, 2026
14	Rssi Onezero Solutions	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	33 contacts →
	Indirect evidence “In October 2021, OneZero Solutions, LCC (OneZero), a leading federal cybersecurity and IT solutions provider, announced its acquisition of Right-Sized Solutions Inc.(RSSi), a…” Source: RevenueBase Database · checked Sep 21, 2026
15	Roka Security, LLC	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	11-50	27 contacts →
	Partial evidence “Roka Security, LLC is a computer security firm located in the Washington D.C.” Source: RevenueBase Database · checked Sep 21, 2026
16	IP Network Solutions	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	26 contacts →
	Indirect evidence “At IPNS, we work exclusively in the Federal marketplace, providing agencies in the Civilian, Defense and Intelligence communities with advanced IT systems solutions and…” Source: RevenueBase Database · checked Sep 21, 2026
17	Vissat Solutions	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	11-50	23 contacts →
	Indirect evidence “Vissat Solutions, Inc is a Virginia-based small business founded in 2005.” Source: RevenueBase Database · checked Sep 21, 2026
18	KLC Network Services, INC	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	16 contacts →
	Indirect evidence “KLC Network Services, Incorporated is an SBA business based in Herndon, Virginia that provides technical solutions to our valued customers.” Source: RevenueBase Database · checked Sep 21, 2026
19	Iosentrix	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	11-50	13 contacts →
	Indirect evidence “ioSENTRIX is a Cybersecurity Consulting firm.” Source: RevenueBase Database · checked Sep 21, 2026
20	Anthony Timbers LLC	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	1-10	11 contacts →
	Indirect evidence “After years of experience working with the Federal Government, it is apparent that cybersecurity is not operating at its highest potential.” Source: RevenueBase Database · checked Sep 21, 2026
21	The Reckon Crew	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	1-10	9 contacts →
	Indirect evidence “At Reckon, we are the vanguard of a new era in government IT consulting, a small but mighty startup driven by a mission to empower government agencies with cutting-edge technology…” Source: RevenueBase Database · checked Sep 21, 2026
22	ISI Enterprises	Partial evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	5 contacts →
	Partial evidence “A leader in security for government contractors, IsI offers end-to-end solutions that simplify the complex.” Source: RevenueBase Database · checked Sep 21, 2026
23	Aristi Technologies, INC	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	1-10	4 contacts →
	Indirect evidence “Aristi is a cybersecurity firm based in the Washington DC metro area.” Source: RevenueBase Database · checked Sep 21, 2026
24	SI	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	11-50	3 contacts →
	Indirect evidence “SI is a professional services firm and government contractor in the investigations, intelligence, and cyber sectors, based in the Washington DC metropolitan area, operating…” Source: RevenueBase Database · checked Sep 21, 2026
25	Tek-Star Corporation	Indirect evidence	Herndon, VA, United StatesHQ checked Sep 21, 2026	51-200	2 contacts →
	Indirect evidence “At TEK-STAR Corporation, we provide a wide range of IT services and consulting expertise to address your organization’s technological needs.” Source: RevenueBase Database · checked Sep 21, 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: biggest security 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 biggest security companies.
Partial evidence: Its own public description names part of biggest security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name biggest security 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 25 of 43 biggest security companies based in Herndon, United States

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Biggest security companies based in Herndon, United States at a glance

As of Sep 21, 2026

25.6%Verified-email coverage

319.3Average contacts per company

11-50Median size (employees)

497.7%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured across the whole United States list rather than for Herndon, so it is reported there. Company counts and contact totals on this page are exact for Herndon, over 43 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 biggest security 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 Herndon, United States whose own description of what they do matches “biggest security 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 biggest security 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 biggest security companies, and records with no verified work email. Companies headquartered outside Herndon 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, 3,508 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.

Biggest security companies by metro in the United States

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 biggest security 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 biggest security companies are there based in Herndon, United States?

RevenueBase identified 43 biggest security companies headquartered in Herndon, 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?

Mantech, headquartered in Herndon, tops this list with the largest team on record.

Which city has the most biggest security companies?

New York leads with 214 headquartered companies, followed by Houston (149) and Washington (143).

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 3,508 verified decision-maker contacts tracked across these 43 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.