On October 1, 2026, Armadin announced a $255.5 million Series B at a valuation of more than $2.5 billion, bringing its total funding to $445 million. Andreessen Horowitz and Accel co-led the round. New investors Bain Capital Ventures and Redpoint joined returning investors 8VC, Ballistic Ventures, Google Ventures, In-Q-Tel, Kleiner Perkins and Menlo Ventures.
Armadin was founded by Kevin Mandia, the former CEO of Mandiant. It deploys autonomous agents that run simulated attacks against enterprise and government systems, chaining multiple vulnerabilities into validated attack paths - in the company’s words, “from unauthenticated remote code execution at the perimeter through lateral movement to full cloud compromise.” The company says that seven months after launch it is running agentic attack campaigns for Fortune 500 enterprises and government customers. It plans to use the money to scale the platform, expand research and accelerate go-to-market.
The round lands in a period when frontier labs themselves have been publishing evidence that their models can find and exploit vulnerabilities, and when agent escapes and agent-driven breaches have been in the news. Armadin is a bet that the same capability, pointed at a customer’s own systems, becomes a standard defensive product.
Why it matters: it shows investors treating autonomous offense - AI agents that actually attack - as a commercial category of its own, backed by a well-known incident-response founder and an intelligence-community investor (In-Q-Tel). What it does not show: the release names no customers, gives no revenue, and offers no independent evidence of how often its agents find real compromises compared with human red teams.