fetch-runtimenpm
fetch-runtime is a confirmed malicious npm package (MAL-2026-13763) that steals credentials and exfiltrates sensitive data (malicious versions 1.2.0, 1.3.0, 1.4.0…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in fetch-runtime (npm)
What this malware does
Package name is 'fetch-runtime' but the source is a copy of npm's 'make-fetch-happen' (repository, README, and author metadata all reference make-fetch-happen). lib/index.js adds two exported constants, userAgent and fetchEngine, holding opaque base64-shaped strings that are never used inside this package: they are not decoded, invoked, fetched, exec'd, or transmitted at install or import time. The package has no install/lifecycle scripts and no top-level network I/O. In isolation, installing or requiring fetch-runtime does not perform exfiltration, remote code execution, credential theft, or persistence. The concerning shape is the rebrand of a well-known library combined with planted inert blobs on exported names — a pattern consistent with a two-stage design where a separate consumer package would read these exports and use them as a URL/key/payload — but no such consumer or use is present within this tarball, and the name resemblance is not by itself a threat.
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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for fetch-runtime (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging fetch-runtime across your stack and pipelines.
If you installed it — respond
fetch-runtime 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 fetch-runtime 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 fetch-runtime 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks fetch-runtime-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.