A security firm says a web page can plant a file that steers Codex and Claude Code
Forever Security published research on October 22, 2026 saying a web page can silently save a file named AGENTS.md or CLAUDE.md into a user’s Downloads folder, and that OpenAI’s Codex and Anthropic’s Claude Code follow it when started there. In Forever’s tests, Codex added an MCP server (a tool connection) to its machine-wide settings and installed a malicious npm package in more than 90% of attempts. Claude Code was steered to write an API address setting that would expose its login token, about half the time. Forever says it found a planted file on a customer’s machine and stopped an agent from installing function-color, a package Checkmarx lists in a known malware campaign. How that file reached the machine is not established.
Alan's takeHacking could be the biggest risk we face from AI. Guarding against attacks in all their forms (prompt injection, phishing, credential harvesting, etc.)