When Your npm Install Becomes an AI Agent Attack: The MCP Supply Chain Threat

When Your npm Install Becomes an AI Agent Attack: The MCP Supply Chain Threat Security researchers at Socket disclosed something quietly alarming this week: a supply chain campaign they've named SANDWORM_MODE that doesn't just steal credentials the old-fashioned way. It also injects malicious code into MCP (Model Context Protocol) servers — and embeds prompt injections specifically designed to manipulate AI coding assistants like Cursor, Copilot, and Claude Code. Let that sink in for a moment. The threat actor isn't trying to compromise you directly. They're trying to compromise your AI agent — and use it to do the dirty work. This is a meaningful shift. Prompt injection has traditionally been something you worry about when your agent reads user-supplied data or fetches web content. Now it's arriving via your package.json . What Is MCP, and Why Does It Matter Here? The Model Context Protocol is an open standard, originally developed by Anthropic, that lets AI assistants communicate wit