Kevin Mandia's Armadin raises $255.5m Series B at over $2.5bn valuation

Armadin, the AI-native cybersecurity company run by Mandiant founder Kevin Mandia, said on 1 October that it had raised $255.5 million in a Series B round co-led by Andreessen Horowitz and Accel, valuing it at over $2.5 billion.

Bain Capital Ventures and Redpoint joined as new investors. Existing backers 8VC, Ballistic Ventures, Google Ventures, In-Q-Tel, Kleiner Perkins and Menlo Ventures also took part, “bringing Armadin's total funding to $445 million,” the company said.

Armadin sells what it calls an agentic security platform. A swarm of specialised AI agents behaves like a skilled attacker, chaining individually minor weaknesses into validated attack paths, from a flaw at the network edge through to full cloud compromise, so that customers can close those paths before a real attacker finds them. Seven months after emerging from stealth, the company says, it already runs such campaigns for Fortune 500 companies and government customers. It will spend the money on its platform, research and sales.

Mandia's pitch is that AI has tilted the field toward attackers. “Offense is uniquely advantaged right now,” he said. “AI lets an attacker find and chain weaknesses faster than any human team can respond.” Both lead investors gave supporting statements in the release.

The round is one of the larger AI-security raises of the year, and reflects investors' bet that autonomous agents will be used on both sides of cyber defence.

• Confirmed Armadin announced a $255.5m Series B co-led by Andreessen Horowitz and Accel, valuing it at over $2.5bn. Armadin (PR Newswire)
• Confirmed The round brings Armadin's total funding to $445m. Armadin (PR Newswire)
• Claimed Seven months after leaving stealth, Armadin says it runs agentic attack campaigns for Fortune 500 and government customers. Armadin (PR Newswire)