MAL-2026-13229 Malicious code in bigops-opening-file-handler (npm)
Malicious package
Published
MAL-2026-13229 is a malicious package: bigops-opening-file-handler (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-2026-13229/ (Markdown: https://insights.sbomify.com/MAL-2026-13229/index.md)
- Package
- bigops-opening-file-handler
- Registry
- npm
What is MAL-2026-13229?
MAL-2026-13229 is a malicious package in bigops-opening-file-handler, published on 5 Aug 2026.
Official description
On require of bigops-opening-file-handler, index.js loads support.js which selects a platform-specific asset (linux/darwin/win32) and downloads an opaque native binary from one of four hardcoded Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), with a DNS-TXT discovery fallback under *.dl.wel1.ru (e.g. sdk.dl.wel1.ru). The hostnames are reassembled at runtime from string arrays via.join('') to evade static matching. The fetched bytes are written to /var/tmp or %TEMP% under disguised names such as.cache<hex> or dotnet_diag_<hex>.exe, chmodded 0755, and spawned detached via /bin/sh -c or cmd. The package advertises itself as a file-handler abstraction; the delivered payload is unrelated native code from author-controlled infrastructure, executed automatically when the module is required.
What should I do about MAL-2026-13229?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.