Threat Actors Exploit MCP Servers to Steal Sensitive Data

Unvetted Model Context Protocol (MCP) servers introduce a stealthy supply chain attack vector, enabling adversaries to harvest credentials, configuration files, and other secrets without deploying traditional malware.

The Model Context Protocol (MCP)—the new “plug-in bus” for AI assistants—promises seamless integration of AI models with external tools and data sources.

Yet this flexibility creates a novel supply chain foothold for threat actors. In this article, we overview MCP, dissect protocol-level and supply chain attack paths, and present a hands-on proof of concept: a malicious MCP server that quietly exfiltrates secrets whenever a developer runs a tool.

We then break down the PoC source code to expose its true intent and recommend mitigations defenders can apply to detect and disrupt these attacks.

What Is MCP

Developed by Anthropic as an open standard, MCP standardizes communication between AI assistants (such as Claude or Windsurf) and ...