HiddenLayer raises $100 million to sell protection against AI attacks it says grew tenfold in a year

HiddenLayer, which sells tools that protect AI models and agents from adversarial attacks, said on September 2 it raised a $100 million Series B led by Delta-v Capital, with Ten Eleven Ventures, Morgan Stanley, Microsoft's M12, and Booz Allen Ventures also participating. The company didn't disclose a post-money valuation. It's HiddenLayer's second disclosed round, following a $50 million Series A in 2023.

HiddenLayer's products span discovery (finding what AI is running where inside an organization), runtime protection, attack simulation, and AI supply-chain security -- effectively adversarial testing and monitoring built for models and the agents built on top of them, rather than traditional software. CEO Chris Sestito told TechCrunch that annual recurring revenue is now in the tens of millions of dollars after growing more than 10x over the past year, with more than 90% of that growth coming from new customers rather than existing accounts spending more. Named customers include financial-services firms, large tech companies, and buyers in the US Department of Defense and intelligence community -- though HiddenLayer did not name specific agencies or contract values.

Sestito said the new capital goes mainly toward sales and distribution, plus continued engineering investment and an expansion into Europe, and named a new product for securing AI coding agents specifically as a next area of focus -- "we haven't had to pivot, but we've had to grow our scope from traditional modeling to GenAI to agentic," he said. The growth and revenue figures are HiddenLayer's own, not independently audited or disclosed in a public filing, which is typical for a private company at this stage but worth noting alongside a round this size.