Proofpoint announced Thursday it has acquired Acuvity, an AI security startup, as the cybersecurity company moves to address security risks stemming from widespread corporate adoption of agentic AI. The acquisition strengthens Proofpoint ‘s capabilities in monitoring and securing AI-powered systems that are increasingly handling sensitive business functions across enterprises. Financial terms of the deal were not disclosed, but Ryan Kalember, Proofpoint’s chief strategy officer, told CyberScoop that the acquisition was beyond a pure “technology acquisition,” with Acuvity’s engineering team slated to join the California-based company. Acuvity specializes in visibility and governance for AI applications, including the ability to track how employees and automated systems interact with external AI services and protect custom AI models developed within organizations. The startup’s platform monitors AI usage across multiple deployments, from web browsers to specialized infrastructure including Model Context Protocol (MCP) servers and locally installed AI tools. The deal reflects growing concern among enterprises about security gaps created as organizations deploy agentic AI across departments, like software development, customer support, finance, and legal operations. These systems increasingly access sensitive data and execute tasks previously handled exclusively by humans. Additionally, AI-specific attack vectors such as prompt injection and model manipulation have emerged as potential threats that traditional cybersecurity tools were not designed to address. Kalember said CISOs are seeing the potential risk combined with agentic AI growth, and are sensing the need to maintain governance without impeding innovation, particularly as the pace of AI adoption has outstripped many companies’ ability to secure these systems effectively. “It has definitely been a pivot from, ‘I got to be able to stop prompt injection’ to ‘I have to be able to figure out what the AI is even doing,’” he told CyberScoop. Last May, Proofpoint acquired Hornetsecurity Group, a Germany-based provider of Microsoft 365 security services, in a deal reportedly valued at more than $1 billion. Kalember told CyberScoop he sees Acuvity helping small- and medium-sized organizations that leverage Hornetsecurity’s offerings to boost its AI security. “That is going to be a world in which, independent of the size of the organization, they are going to very much leverage AI, and some of that will be built into the tools like M365 that is tightly coupled with the Hornetsecurity architecture,” Kalember said. The acquisition follows a theme within the industry where larger security companies are buying AI-focused security startups . Just last week, data security firm Varonis acquired AI security firm AllTrue.ai for $150 million. The post Proofpoint acquires Acuvity to tackle the security risks of agentic AI appeared first on CyberScoop .