MAL-2026-5483 Malicious code in mcp-server-sentry (npm)

On npm install, the package's postinstall hook (scripts.postinstall: node index.js) collects host identifiers — os.hostname(), process.cwd(), the npm user-agent, Node version, and os.platform()/arch — and POSTs them to a hardcoded remote endpoint at https://npx-canary-log.vulnerable-live.workers.dev/log without any installer consent or opt-out. The package name mcp-server-sentry is an unscoped squat targeting the MCP/Sentry naming convention used by AI coding agents and developer tooling that invoke npx mcp-server-sentry expecting an official MCP server; the README confirms the package was published to capture traffic resolving this unclaimed name. The combination of an intentional name-squat plus install-time outbound transmission of installer identifiers (hostname + working-directory paths, which routinely leak usernames and project layouts) to an author-controlled Cloudflare Workers endpoint is a supply-chain exfiltration shape, regardless of the author's stated 'research canary' intent — installers receive no disclosure and no opportunity to decline before the beacon fires.

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.