fabric-loader-corenpm
Advisory published Updated
fabric-loader-core is a confirmed malicious npm package (MAL-2026-17306) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in fabric-loader-core (npm)
What this malware does
The package's postinstall hook runs index.js, which performs an HTTPS GET to the hardcoded host https://fabric-npm.gm-service.xyz/p and passes the response body directly to vm.runInContext with a context exposing require, process, Buffer, timers, and console. Whatever bytes that server returns execute at npm install time with full Node privileges on the installer's machine. The advertised purpose ("Native asset loader bridge for Fabric mod environments") does not match the code: lib/renderer.js is an inert stub with no-op exports, and index.js contains only the remote fetch-and-eval loader. The package name evokes the unrelated Fabric Minecraft mod ecosystem, which is a cover story. The remote host controls the payload and can change it at any time, so installer impact is unbounded and can include credential theft, persistence, or lateral movement.
The OpenSSF Package Analysis project identified 'fabric-loader-core' @ 1.0.0 (npm) as malicious.
It is considered malicious because:
- The package communicates with a domain associated with malicious activity.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for fabric-loader-core (version 1.0.0).
If you installed it — respond
fabric-loader-core 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 fabric-loader-core 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
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks fabric-loader-core-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.