Security Startups

Armadin

Offensive security platform that sends swarms of AI attacker agents against an organization's attack surface to exploit weaknesses and chain them into validated attack paths.

Proof of life. Raised a $255.5M Series B co-led by Andreessen Horowitz and Accel at a valuation above $2.5B, October 2026

About Armadin

Armadin, a Palo Alto company led by Mandiant founder Kevin Mandia, runs swarms of specialized AI agents that probe an organization's attack surface, attempt exploits and chain small issues into validated attack paths, for example from an internet-facing flaw through lateral movement to sensitive cloud resources.

Customers see those paths and their potential blast radius. Every agent action passes through a control layer overseen by a safety model that the company says was trained with feedback from human security experts.

It sells to enterprises and government agencies. The company reports running campaigns in production for Fortune 500 and government customers, and has raised about $445M in total.

Investors

Andreessen HorowitzAccelBain Capital VenturesRedpoint8VCBallistic VenturesGVIn-Q-TelKleiner PerkinsMenlo Ventures
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