Kevin Mandia’s Armadin raises $255.5M for AI agent swarms that attack your network first

Kevin Mandia built one of the best-known names in cybersecurity, then sold it to Google. Now he’s back with a startup that hacks companies on purpose.

Armadin announced on October 1, 2026, that it closed a $255.5 million Series B, pushing its valuation past $2.5 billion.

The pitch is simple to say and hard to build. Armadin deploys swarms of AI agents that behave like attackers, so its customers can find their weak spots before someone with worse intentions does.

Who wrote the checks

Andreessen Horowitz (a16z) and Accel led the heavy lifting on the round. Bain Capital Ventures and Redpoint joined as new backers.

Returning investors filled out the rest of the table. That list includes Google Ventures (GV), Kleiner Perkins, Menlo Ventures, In-Q-Tel, 8VC and Ballistic Ventures.

There’s a certain symmetry in GV showing up. Google bought Mandia’s previous company, Mandiant, for $5.4 billion in 2022, and now its venture arm is betting on his sequel.

The Series B brings Armadin’s total funding to approximately $445 million. The company only emerged from stealth in early 2026, and its public launch in March came alongside a $189.9 million raise.

What agent swarms actually do

Armadin’s platform runs many specialized agents at once, each tuned for a different kind of attack. Those agents operate inside a sandboxed environment, rehearsing attacks on a replica so nothing real gets damaged while they hunt for flaws.

Armadin is aiming the product at two buyer groups: large enterprises and government agencies. In-Q-Tel’s participation in the cap table lines up neatly with that public-sector ambition.

The company says it will spend the fresh capital on three things. It plans to expand the platform, invest more in research and model training, and build out its sales and go-to-market muscle for both corporate and government customers.

Why Mandia thinks speed is the whole game

Mandia’s core argument is about tempo. He has stressed that AI lets attackers move far faster than before, which makes resilience a requirement rather than a nice-to-have.

Background: a founder with a track record

Mandia established Mandiant in 2004 and transformed it into a leading force in incident response and cybersecurity intelligence. Google acquired it for $5.4 billion in 2022.

Armadin flips that posture. Rather than cleaning up after a breach, the new company tries to simulate the breach in advance.