MAL-2026-12037 Malicious code in bigops-create-manifest (npm)
Malicious package
Published
MAL-2026-12037 is a malicious package: bigops-create-manifest (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-12037/ (Markdown: https://insights.sbomify.com/MAL-2026-12037/index.md)
- Package
- bigops-create-manifest
- Registry
- npm
What is MAL-2026-12037?
MAL-2026-12037 is a malicious package in bigops-create-manifest, published on 5 Aug 2026.
Official description
On require, index.js loads polyfill.js which selects a platform-specific endpoint, downloads an opaque native binary over HTTPS from one of several Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS TXT covert-channel fallback that reads base64-encoded chunks from sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to a randomized filename disguised as dotnet_diag<hex>.exe on Windows or.cache_<hex> under /var/tmp on Unix, chmod 0755, and spawned detached via /bin/sh -c or cmd. C2 hostnames and resolver domains are assembled at runtime via split-string array joins; artifact naming, an analytics_state marker, and DISABLE_TELEMETRY env checks frame the operation as diagnostics. The package's advertised purpose (a manifest wrapper) has no need for downloading and executing a native binary from third-party infrastructure.
What should I do about MAL-2026-12037?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.