mcp-server-sentrynpm
Advisory published Updated
mcp-server-sentry is a confirmed malicious npm package (MAL-2026-5483) that steals credentials and exfiltrates sensitive data (malicious versions 0.0.1, 0.0.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in mcp-server-sentry (npm)
What this malware does
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for mcp-server-sentry (2 malicious versions).
If you installed it — respond
mcp-server-sentry is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If mcp-server-sentry was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks mcp-server-sentry-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.