Armadin Inc. raised $255.5 million in a Series B round to develop autonomous AI agents that probe enterprise systems and simulate cyberattacks, effectively automating the red-teaming work that security firms have traditionally staffed with human penetration testers.
The round is part of a broader investment pattern in 2026: as AI agents become capable enough to be a genuine security threat vector in the wrong hands, a parallel market has emerged for AI agents that defend against exactly that threat, often built by teams with direct experience on the offensive side of security research.