Kevin Mandia's new security firm Armadin uses AI agents to hunt for zero-days

a16z says Armadin's AI agents map networks from the outside and re-attack when something changes. It says the agents have found 90-plus zero-days at Fortune 500 companies since January 2026, while autonomous patching remains a goal. In a separate post, a16z's David George quotes Mandia warning that the next year in cybersecurity won't be “pretty.”