Estonia-based Blackwall, which builds web traffic security tools for hosting providers, said on Tuesday that it has raised $100 million at a $2.2 billion valuation. It builds products that helps websites grapple with the skyrocketing volume of bot traffic, especially AI agents.

The Series C was led by AVP, with participation from existing investors Dawn Capital, MMC Ventures and Tera Ventures. Blackwall’s executive chairman, Roi Carthy, told TechCrunch this funding round increased the company’s valuation by 4 times since its previous fundraise in 2025.

Over the past few years, web infrastructure companies like Cloudflare, Akamai, Imperva and Blackwall have found themselves in an increasingly valuable but difficult space: They’re on the frontlines, dealing with DDoS attacks, indiscriminate scraping, botnet farms, malicious requests, and these days, even swarms of AI agents going rogue. But it’s also a chance to make a killing by helping hosting providers and websites deal with all the potentially unwanted traffic.

Blackwall, however, isn’t interested in competing with the bigwigs in its space. Instead of selling its platform directly to websites, the company uses a “channel” approach, working with web hosting, managed service and cloud providers to understand their needs, and then handing over a bundle of tools which they can customize. Those providers can then offer Blackwall’s security tools to their own clients under their own branding and retain control of that relationship.

There’s money in it for both sides. Co-founder and CEO Nikita Rozenberg told TechCrunch that hosting companies can mix and match security components to build their own solution according to what they want to provide to their end customers, set the prices, and share a cut of the revenue with Blackwall. The company initially gives its customers a free tier showing the traffic and threats hitting their network, but charges for any protection or tools to address the threats.

In addition to providing services like threat intelligence, certificate management, DDoS protection and traffic routing, Blackwall examines its customers’ web traffic to differentiate actual visitors and legit AI agents from malicious bots, intruders, and disruptive traffic. Rozenberg said the company uses techniques like digital fingerprinting to identify the software sending a request — for example, Microsoft Office or Codex — to filter out bots. In addition, the company uses its own AI models at customers’ endpoints to analyze the intent and behavior of the requests coming in to differentiate agents sent by a person for a real request versus a malicious bot.

In the coming years, Rozenberg sees a big opportunity emerging as AI agents begin interacting and transacting with websites on behalf of their users. This should eventually require systems to manage which agents get access, and on what terms, and how they are authorized to make payments.

Blackwall isn’t alone in eyeing that opportunity. Cloudflare’s AI Crawl Control lets website owners allow or block individual AI crawlers, and there’s also an option to charge them for access. But Rozenberg argues that Blackwall’s advantage lies in letting hosting providers offer such traffic management services themselves instead of handing the customer relationship to another security provider.

Blackwall plans to use the funding to expand its operations across North America, Europe, Asia-Pacific and the Middle East, and develop more security tooling for hosting, cloud and managed service providers.