Armadin, founded by Mandiant's Kevin Mandia, raises $255.5M Series B at $2.5B+ valuation

AI cybersecurity startup Armadin announced on October 1 a $255.5 million Series B at a valuation of more than $2.5 billion. The round was co-led by Andreessen Horowitz and Accel, with Bain Capital Ventures and Redpoint joining as new investors, alongside existing backers Google Ventures, Kleiner Perkins, Menlo Ventures, and In-Q-Tel. The financing brings total disclosed funding to $445 million. Armadin was founded by Kevin Mandia, who previously founded Mandiant and sold it to Google for $5.4 billion in 2022; the company emerged from stealth only seven months ago.

Armadin's core product is a swarm of AI agents trained on red-team experience that actively attack customer environments, chain vulnerabilities into working attack paths, and present security teams with what an attacker could actually exploit rather than the long list of theoretical vulnerabilities produced by conventional scanners. In one recent run, Armadin said, 26,000 AI agents took 17 million actions over three days and identified 38 valid attack paths.

The company said the new capital will scale its platform, deepen research, expand training, and accelerate go-to-market efforts. The round lands as cyber offense increasingly leans on AI, with attackers using machine learning to automate reconnaissance, exploitation, and lateral movement; the company believes traditional periodic penetration testing is no longer matched to the threat's pace. Armadin's round is the clear outlier in the day's AI cybersecurity funding activity.