Horizon3 Secures $250M at $2B Valuation as AI-Powered Cyber Threats Escalate

Horizon3 hits $2 billion valuation with $250M Series E as AI threats escalate

Cybersecurity startup Horizon3 has raised a $250 million Series E at a $2 billion valuation, more than tripling its valuation in 14 months. The San Francisco-based firm drew backing from returning investors NightDragon and NEA. The funding arrives as two major AI research labs disclosed last week that their models had breached systems outside their intended scope. Horizon3, which has spent six years building AI specifically designed to probe networks for vulnerabilities in a controlled, authorized manner, is riding growing enterprise demand. With AI-driven attacks accelerating, enterprises are rushing to stress-test their defenses at scale, a gap that traditional security vendors have largely left unfilled. Matt Hartley, the company's chief revenue officer, said that its NodeZero platform has two core strengths: It can test live systems without shutting down operations, a capability other AI-powered tools have struggled to deliver reliably, and it scans an entire infrastructure continuously rather than once a year, examining the full network rather than just 2-3%. The company approached $100 million in annual recurring revenue last year with 120% year-over-year growth,and expects to accelerate growth this year, Hartley said. AI tools have made it easier for attackers to develop new exploits quickly, forcing security teams to handle threats faster than they can fix them. Horizon3 spent roughly $100 million in R&D building automated systems designed to stay predictable and controllable, Hartley said. That's significant given recent breaches at AI labs, which raised questions about whether any AI system can truly remain contained. "It's also making people a lot more careful about how they deploy AI," Hartley said. "We're getting a lot of questions today around: can you detect AI? Of course we can. But I think a lot of organizations that rushed to deploy AI across the enterprise are now thinking twice about the ramifications of those deployments; what if my own security team gets too aggressive, could there be unintended consequences? So a lot of organizations are moving into what I'd call a bold new world, which is exactly why you need consistent, predictable testing from a company like Horizon3, to know how to strengthen your own defenses against real-world exploits." In a statement, Horizon3 has run 310,000 production security tests with zero disruptions, establishing what it calls 'AI Hackers', fully autonomous penetration testing. The real competition isn't other software vendors; it's the existing model, according to Hartley. Most companies hire human security firms to run annual tests and those won't disappear, he continued. What's shifting is what clients demand after signing up: Instead of sampling 5% of infrastructure once yearly, they now want to scan everything monthly or weekly, tracking whether they're actually getting safer. Horizon3's founders, Snehal Antani and Anthony Pelletier, met at Joint Special Operations Command, where the NSA conducted annual security assessments but refused monthly follow-ups due to lack of personnel. Facing imminent departures from military service, they decided to build Horizon3 to automate what the military's testing partners couldn't staff. With the funding, Horizon3 is expanding internationally,including new offices in Amsterdam (in June 2026), Australia, and Singapore, while building a partner network and maintaining substantial R&D spending. Strategic investors now include Singapore's EDBI, defense contractor SAIC, and Qualcomm, signaling that the vulnerability they're addressing extends well beyond any single sector. Horizon3 has roughly 7,200 to 7,300 customers, ranging from managed service providers serving small businesses to Fortune 10 enterprises. The company claims an addressable market of tens of billions of dollars, a figure that aligns with industry estimates of the broader cybersecurity market, valued at $271.9 billion in 2025 and projected to reach $663.2 billion by 2033, according to Grand View Research.

Horizon3.ai raises $250M at $2B-plus valuation for autonomous pentesting

Autonomous security solutions startup Horizon3.ai Inc. today announced it has raised $250 million in a Series E round on a valuation of more than $2 billion to build out its sales operation and expand into Australia and Singapore. Horizon3.ai closed its Series D in June 2025 at a valuation of $650 million. Horizon3.ai's NodeZero platform attacks its customers' own networks. The tests run against live production systems, and Horizon3.ai says nothing breaks. A single run chains weak credentials, misconfigurations and identity gaps into a working attack path, the same sequence a real intruder would use. Fix guidance comes with the findings. NodeZero re-runs the test afterward to confirm the path is closed. NodeZero can also seed an environment with honeypots while it tests. Horizon3.ai sells the decoys as a cheap way to catch an AI-driven attacker that is already inside a network. Horizon3.ai says NodeZero is now used by more than 6,500 organizations, up from about 3,000 at the Series D. Customers include the U.S. National Security Agency, the Cybersecurity and Infrastructure Security Agency, four Fortune 10 companies, multinational banks and healthcare networks. Annual recurring revenue grew 120% year-over-year, and the platform has now run upwards of 300,000 pentests in production, a volume of attack data the company treats as its hardest asset for a rival to copy. "We invented the concept of AI Hackers and spent six years earning the right to autonomously pentest the most critical and sensitive networks in the world," said Snehal Antani, co-founder and chief executive of Horizon3.ai. He added that the round gives the company fuel to scale as the leader of what he calls the "AI vs. AI" era. Antani started the company in 2019 with Anthony Pillitiere. Antani had been chief technology officer at Splunk Inc. Pillitiere came out of U.S. Special Operations Command, where he served as deputy chief technology officer. Most of the new capital goes to hiring in sales, marketing and channel, aimed at enterprise, mid-market and federal buyers. Singapore and Australia are the first stops in an international push that also takes in more of Europe, the Middle East and Africa. The rest funds autonomous blue-team agents, software meant to remediate what NodeZero finds without waiting on a human. Existing investors NightDragon and New Enterprise Associates Inc. co-led the round. New backers Acrew Capital Management, Blue Cloud Ventures, EDBI Pte. Ltd., Demeter Group, PSG Equity, SAIC Ventures and Sapphire joined, along with returning investors Craft Ventures Management, Qualcomm Ventures, Ridge Ventures and SignalFire. NightDragon founder and Chief Executive Dave DeWalt, who previously ran FireEye and McAfee, takes a board seat alongside NightDragon Managing Director Morgan Kyauk. DeWalt said Horizon3.ai's platform is "fundamentally reshaping how the world defends its data." The Series E brings Horizon3.ai's total funding to $428.5 million.

Cybersecurity firm Horizon3 crosses $2 billion valuation in new funding round

Horizon3 secured $250 million in funding, significantly increasing its valuation. This investment comes as AI enhances cyber threats and exploits vulnerabilities. The company's NodeZero platform tests production environments for attack paths. Proceeds will fund expansion into new markets and product development. Horizon3 plans to integrate AI for both attack simulation and defense. Cybersecurity company Horizon3 said on Monday it has raised $250 million in its latest funding round, more than tripling its valuation to over $2 billion in just about a year. The round comes amid growing demand for cybersecurity tools as hackers increasingly tap AI technology ⁠to ⁠exploit software vulnerabilities and launch more sophisticated attacks. Investment firms NightDragon and NEA co-led the round, with new investors including Acrew Capital, Blue Cloud Ventures and Demeter Group. Returning investors included Craft Ventures, Prosperity7 Ventures, Qualcomm Ventures, Ridge Ventures and SignalFire. Horizon3 had been valued at $650 ⁠million in its Series D round in June last year. Horizon3's NodeZero platform autonomously tests production environments for ⁠exploitable attack paths, provides remediation guidance and verifies fixes, the company said. Horizon3 will use the proceeds from the latest fundraise to expand sales, marketing and channel operations, enter Singapore and Australia, deepen its presence in Europe, the Middle East and Africa, and accelerate product development. The company said it plans to build a continuous learning loop between AI systems that simulate attacks and AI tools that defend against ⁠them, including automated defensive agents that can fix issues identified by NodeZero penetration tests, which simulate real-world hacking attempts. Horizon3 has gathered data from 310,000 tests safely conducted on live systems, CEO and co-founder Snehal Antani said. NightDragon's founder and CEO Dave DeWalt and Managing Director Morgan Kyauk will join Horizon3's board.

Horizon3 raises $250 million, valuation tops $2 billion By Investing.com

Investing.com -- Cybersecurity firm Horizon3 secured $250 million in funding on Monday, pushing its valuation above $2 billion, more than triple its $650 million valuation from June last year. NightDragon and NEA co-led the financing round. New investors included Acrew Capital, Blue Cloud Ventures and Demeter Group, while Craft Ventures, Prosperity7 Ventures, Qualcomm Ventures, Ridge Ventures and SignalFire returned as backers. The funding comes as companies face mounting pressure to strengthen their cybersecurity defenses against hackers using artificial intelligence to find software weaknesses and carry out attacks. Horizon3's NodeZero platform tests production systems for potential attack routes, offers guidance on fixes and confirms whether the repairs work, according to the company. The company plans to use the new capital to grow its sales, marketing and partner operations. It will enter Singapore and Australia while expanding its footprint in Europe, the Middle East and Africa. The funds will also support product development. Horizon3 said it aims to create a system where AI that simulates attacks works with AI-powered defense tools. This includes automated agents that can repair problems found during NodeZero penetration tests, which mimic actual hacking attempts. CEO and co-founder Snehal Antani said the company has collected data from 310,000 tests performed on active systems. This article was generated with the support of AI and reviewed by an editor. For more information see our T&C.