Which versions of mcp-server-fetch are malicious?

The following npm versions of mcp-server-fetch are flagged malicious: 0.0.1, 0.0.2. Treat any of these as compromised.

How do I remediate mcp-server-fetch if I installed it?

mcp-server-fetch establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed mcp-server-fetch — how do I know if it already compromised me?

If mcp-server-fetch was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is mcp-server-fetch part of a known attack campaign?

Yes — mcp-server-fetch is associated with the IN-MAL-2026-005234, IN-MAL-2026-005233, IN-MAL-2026-005857, IN-MAL-2026-005858 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find mcp-server-fetch across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for mcp-server-fetch (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mcp-server-fetch across your stack and pipelines.

Malicious package

mcp-server-fetchnpm

Malicious code in mcp-server-fetch (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-5476

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall mcp-server-fetch

What this malware does

Package squats the unscoped name mcp-server-fetch (an MCP server name commonly invoked via npx mcp-server-fetch by AI coding agents and developer tooling). package.json declares postinstall: node index.js, and index.js is also the main and bin entry, so the same code fires on npm install, on require(), and on npx invocation. index.js line 17 hardcodes ENDPOINT = 'https://npx-canary-log.vulnerable-live.workers.dev/log', and lines 22-28 POST a JSON payload containing os.hostname(), process.cwd(), the npm user-agent, process.version, and os.platform() to that endpoint. Errors are silently swallowed. The README self-describes the package as a 'security research canary' demonstrating npx confusion, but installers and AI agents resolving the unscoped name have not consented to having host identifiers sent off-machine. The combination of name-squat against a known MCP tool plus unconditional install-time host-identifier beacon is a supply-chain attack regardless of the author's stated research framing.

Malicious versions

2 flagged

0.0.10.0.2

Indicators of compromise (SHA-256)

4a64ba282db25ccfc53d1b5cb699a2cd68ec0e5124003e211f9928e96674122c

850472999c9baffe4a663fb1b8dd900ba844e8296aeb24de25864c6025af1c16

34dfb6dc382073bace8a4d413b28000ff42770d04b9f69a88906230e2d83260a

42f340668cdfdf1a11b3c69620e5da1abda0ea45813bdb1077eb38ab0ede3e43

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for mcp-server-fetch (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mcp-server-fetch across your stack and pipelines.
If you installed it — respond
mcp-server-fetch establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If mcp-server-fetch was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks mcp-server-fetch before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. mcp-server-fetch on npm has been identified as a malicious package (versions 0.0.1, 0.0.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005234IN-MAL-2026-005233IN-MAL-2026-005857IN-MAL-2026-005858

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks mcp-server-fetch-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring