Armadin, a cybersecurity startup that uses AI agents to carry out controlled attacks and identify weaknesses hackers could exploit, has raised $255.5 million in Series B funding at a valuation of more than $2.5 billion.
Andreessen Horowitz and Accel co-led the round, with participation from new investors Bain Capital Ventures and Redpoint, Armadin said Thursday.
Existing investors 8VC, Ballistic Ventures, Google Ventures, In-Q-Tel, Kleiner Perkins and Menlo Ventures also participated. The round brings Armadin's total funding to $445 million.
The funding comes seven months after Armadin emerged from stealth with $189.9 million in combined seed and Series A funding.
AI agents test company systems
Armadin said it uses AI agents to find security issues by carrying out controlled attacks on company systems. The agents check if one or more problems can be used to reach other systems or sensitive data.
Armadin said in one of its tests, agents targeted more than 25,000 services, launched 1,300 attacks and found 238 security issues and 38 possible attack paths.
Armadin said it works with Fortune 500 companies and government customers but did not name them.
"AI lets an attacker find and chain weaknesses faster than any human team can respond," Kevin Mandia, CEO of Armadin, said in a statement. "The only way to build a defense that keeps pace is to train it against the best offense available, every day."
Led by Mandiant founder
Mandia previously founded cybersecurity company Mandiant and served as CEO of FireEye. He has worked in cybersecurity for more than 30 years, according to Armadin's website.
Google acquired Mandiant for $5.4 billion in 2022 and integrated it into Google Cloud.
"Every major platform shift creates a new generation of security leaders, and AI is the biggest shift we've seen," said Andreessen Horowitz general partner David George. "We invested because we believe Armadin will become the defining security company of the AI era."