Palo Alto Networks closed its acquisition of endpoint security vendor Koi Security, while claiming to have established a new category in AI-driven security.

Highlighting Koi's skills in securing vibe-coding agents and autonomous endpoint tools, Palo Alto Networks said the deal came alongside an inflection point in agentic AI adoption, thus necessitating what it dubbed agentic endpoint security (AES).

The security giant confirmed it would integrate Koi's technology with its AI-centric Prisma Airs platform and a new module for its Cortex XDR endpoint suite to identify and address risks within the AI software ecosystem. The latest iteration of Prisma Airs, released last month, already leveraged Koi by touting an AES provision for full visibility across AI endpoint applications.

Koi’s capabilities will also continue to be available as a standalone offering, Palo Alto Networks added.

Established in January 2024, Koi Security trades in endpoint security posture management (ESPM), in which endpoint devices are inspected through automation for vulnerabilities such as misconfigurations and missing patches.

The Tel Aviv-based firm had raised $48 million prior to the Palo Alto Networks purchase, with a $38 million Series A round last year seeing funding from Battery Ventures, Team8, Picture Capital, NFX, and Cerca Partners. Koi counts between 40 and 50 clients, including OpenAI, Fireblocks, FHLBank Dallas, as well as Palo Alto Networks itself.

Financial details of the deal were not disclosed, but earlier rumors pointed to a $400 million price tag.

Earlier this year, Mauricio Sanchez, senior director at Dell’Oro Group, told this title that Palo Alto Network’s intent to acquire Koi reads as a logical extension of its AI security push.

“As AI agents and copilots are deployed, they function like privileged ‘insiders’ on endpoints, which means visibility and policy control must extend beyond files and processes to the agent tooling itself – plugins, extensions, scripts, and packages,” Sanchez said. “Koi’s value is at the install and supply-chain layer on the endpoint, where extensions and packages are becoming an expanding blind spot for many enterprises.

"Traditional endpoint controls are not consistently designed to govern that layer, so Palo Alto can use Koi to strengthen coverage while positioning it as a platform capability – extending Prisma Airs and improving visibility, policy, and malware prevention within Cortex XDR," Sanchez continued. "By emphasizing ‘agentic endpoint security,’ Palo Alto is labeling an emerging risk surface and aiming to own that control point as AI-native workflows scale.”

The analyst added Palo Alto Networks is treating AI agents and their add-ons as the next major endpoint attack surface, with Koi governing the agentic layer before it becomes an enterprise-wide blind spot.