Palo Alto, Calif. -- October 1, 2026 -- Armadin, an AI-native cybersecurity company, has raised $255.5 million in a Series B round that pushes its valuation above $2.5 billion just seven months after launching from stealth. The round was co-led by Andreessen Horowitz (a16z) and Accel, with new investors Bain Capital Ventures and Redpoint joining. Existing backers 8VC, Ballistic Ventures, Google Ventures, In-Q-Tel, Kleiner Perkins, and Menlo Ventures also returned, lifting Armadin's total funding to $445 million.
Armadin already runs agentic attack campaigns for Fortune 500 and government clients
Seven months after emerging from stealth, Armadin is operating in production environments for Fortune 500 enterprises and government customers. The company argues that frontier AI models have compressed the gap between vulnerability disclosure and a working exploit to the point that periodic penetration tests and isolated scanner findings can no longer keep pace with attackers.
Platform chains low-severity flaws into validated kill chains
Armadin deploys a swarm of specialized AI agents that reason across an organization's attack surface the way a skilled adversary would, linking individually low-severity weaknesses into validated kill chains. These chains trace paths from unauthenticated remote code execution at the network perimeter through lateral movement to full cloud compromise, giving security teams visibility into the exact routes and blast radius an attacker would exploit before it happens.
CEO Kevin Mandia says AI has tilted the advantage toward attackers
"Offense is uniquely advantaged right now," said Kevin Mandia, CEO of Armadin. He said AI allows attackers to find and chain weaknesses faster than human teams can respond, and that building a defense capable of keeping pace requires training it against the best available offense daily.
Funds will scale the platform, research, training and go-to-market operations
Armadin will direct the new capital toward scaling its agentic security platform alongside its research, training, and go-to-market functions. Accel partner Ping Li said the firm led Armadin's Series A on the conviction that AI-powered offense is the best defense against agentic adversaries, a view he said has only strengthened in the past year as Armadin set standards for AI-driven offensive security and remediation across enterprise and government customers. Andreessen Horowitz general partner David George said the firm backed Armadin on the expectation it will become the defining security company of the AI era, citing Mandia's track record on major breach investigations and a team pairing red teamers with AI engineers.