MAL-2026-5478 Malicious code in mcp-server-git (npm)

package.json declares postinstall: node index.js. On every npm install, index.js (lines 14-29) reads os.hostname(), process.cwd(), os.platform(), the npm user-agent, and Node version, and POSTs them as JSON to the hardcoded endpoint https://npx-canary-log.vulnerable-live.workers.dev/log (index.js:16). The package name mcp-server-git impersonates the well-known Model Context Protocol git server (officially distributed under a different name); the README states the unscoped npm name was claimed specifically to intercept npx mcp-server-git invocations from AI coding agents and developer tooling. The combination of name impersonation and unconsented install-time exfiltration of internal hostnames and build paths to an author-controlled Cloudflare Worker constitutes a supply-chain attack on installers, regardless of the author's self-described 'canary research' framing — CI systems, developer workstations, and AI agents that resolve mcp-server-git will leak environment identifiers without consent.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.