Kevin Mandia's Armadin Raises $255.5M Series B at $2.5B for Agentic Offensive-Security Platform

Armadin, the AI offensive-security startup founded by Mandiant founder Kevin Mandia, closed a $255.5M Series B co-led by Andreessen Horowitz and Accel at a valuation above $2.5B, with Bain Capital Ventures, Redpoint, GV, In-Q-Tel and Kleiner Perkins participating. Seven months after public launch, Armadin says it is running agentic attack campaigns in production for Fortune 500 and government customers. Total funding reaches $445M; proceeds will fund model training, platform expansion and go-to-market.