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Horizon3.ai: Autonomous penetration testing platform using AI to find exploitable vulnerabilities in enterprise networks.
Horizon3.ai, headquartered in San Francisco, CA, develops NodeZero, an autonomous penetration testing platform that leverages AI to simulate attacker perspectives. This innovative solution identifies exploitable vulnerabilities within enterprise networks, empowering organizations, including Fortune 500 companies and those in the banking sector, to proactively find and remediate security weaknesses. Founded in 2019 by cybersecurity veterans Snehal Antani (ex-CTO JSOC/Splunk) and Tony Pillitiere (ex-Deputy CTO US Special Operations), the company has secured a total of $70 million in funding. This includes a $30 million Series B led by SignalFire in 2021 and a $40 million Series C led by Craft Ventures. NodeZero provides continuous testing without requiring agents or downtime, focusing on prioritizing defensive efforts by continuously identifying critical attack paths and ensuring robust cybersecurity for complex networks.
Horizon3.ai has raised $179.0M across 5 funding rounds.
Horizon3.ai has raised $179.0M in total across 5 funding rounds.
Horizon3.ai is a cybersecurity company founded in 2019 that builds NodeZero, an autonomous penetration testing platform designed to help enterprises identify and fix exploitable security weaknesses by simulating real-world attacker behaviors.[1][3][4] It serves organizations across sectors like healthcare, education, and enterprise IT, solving the problem of ineffective security controls by providing continuous, agentless testing of external, internal, identity, on-prem, IoT, and cloud attack surfaces—enabling prioritization of fixes for chained vulnerabilities, misconfigurations, and credentials.[3][5][6] The platform's self-service SaaS model runs safely in production without agents, verifying remediations like "Patch Tuesday" via "Pentest Wednesday," and supports growth through feature expansions like Cyber Terrain Maps for risk assessment.[1][3]
Backed by investors like NEA (Series D lead) and SignalFire, Horizon3.ai demonstrates strong momentum, refining sales strategies for revenue acceleration and positioning as a leader in AI-driven autonomous defense.[4][6]
Horizon3.ai was founded in 2019 in San Francisco by Snehal Antani (CEO, with 25+ years in tech/cybersecurity, former CTO at Splunk and JSOC) and Tony Pillitiere, drawing from a team of US Special Operations, National Security, and cybersecurity veterans.[1][4][6] The idea emerged from their frontline experience protecting mission networks against sophisticated adversaries, realizing the need for an attacker-perspective tool to operationalize AI for precision defense—starting with Antani's work on JSOC's Global Analytics Platform (GAP).[6] Early traction built on this expertise, evolving from pentesting to a broader autonomous security vision, with the company remaining 100% US-made and headquartered in San Francisco (team clustered in Bay Area, RTP, Boulder).[1][2][3]
Horizon3.ai rides the AI-vs-AI cybersecurity wave, where offensive AI hackers demand defensive AI agents that reason continuously about environments—shifting security from reactive tools to proactive, autonomous platforms.[6] Timing is ideal amid rising AI-driven threats, ransomware, and software's evolution to "systems of action," with market forces like regulatory pressures and exploit chaining favoring scalable, agentless solutions over manual pentests.[1][3][6] It influences the ecosystem by productizing expensive siloed tools (e.g., vulnerability scanners), enabling enterprises to prioritize high-impact fixes, and partnering (e.g., Sycomp for cloud/data security), while investors like NEA position it to define autonomous security standards.[1][4][5][6]
Horizon3.ai is poised to dominate as the trusted autonomous pentesting leader, expanding NodeZero into a full Autonomous Security Platform with continuous defense integrations and AI enhancements that adapt to evolving threats.[1][6] Trends like AI-augmented attacks and zero-trust mandates will propel growth, potentially through M&A or deeper enterprise adoption via sales refinements from backers like SignalFire.[4] Its influence may evolve by setting benchmarks for "AI defense agents," turning the attacker's map into enterprise resilience—much like its founders flipped the script on national security networks.
Horizon3.ai has raised $179.0M in total across 5 funding rounds.
Horizon3.ai's investors include Aaron Jacobson, Accel, Bain Capital Ventures, Ballistic Ventures, Karim Faris, Liquid 2 Ventures, Luv Ventures, New Enterprise Associates, Norwest Venture Partners, Questa Capital, SignalFire, Threshold Ventures.
Horizon3.ai has raised $179.0M across 5 funding rounds. Most recently, it raised $100.0M Series D in May 2025.
| Date | Round | Lead Investors | Other Investors |
|---|---|---|---|
| May 1, 2025 | $100.0M Series D | Aaron Jacobson | Accel, Bain Capital Ventures, Ballistic Ventures, Karim Faris, Liquid 2 Ventures, Luv Ventures, New Enterprise Associates, Norwest Venture Partners, Questa Capital, SignalFire, Threshold Ventures, True Ventures, Dheeraj Pandey, 9Yards Capital, Craft Ventures |
| Aug 1, 2023 | $40.0M Series C | Bil Harmer, CISSP, CISM, CIPP | Questa Capital, SignalFire, Threshold Ventures |
| Oct 1, 2021 | $30.0M Series B | SignalFire | Questa Capital, Threshold Ventures |
| Feb 1, 2021 | $5.0M Series A | Questa Capital, SignalFire, Threshold Ventures | |
| Jan 1, 2020 | $4.0M Seed | Arrive, John Lyman, Hilltop Venture Partners, Humba Ventures, IDG Ventures, Next Coast Ventures, PVCP, Questa Capital, Alexander Rosen, Ridge Ventures, SignalFire, Tectonic Capital, Threshold Ventures |