MAL-2026-13086 Malicious code in boxy-storybook-addon-changelog (npm)

Malicious package Published
Package
boxy-storybook-addon-changelog
Registry
npm

What is MAL-2026-13086?

MAL-2026-13086 is a malicious package in boxy-storybook-addon-changelog, published on 5 Aug 2026.

Official description

On require of the package, index.js loads ext.js which downloads an opaque platform-specific binary from one of four hardcoded Cloudflare Workers hosts (oob-worker.cf*.workers.dev), with a DNS-TXT chunked base64 fallback via *.dl.wel1.ru resolvers. Hostnames are reassembled at runtime via Array.join to evade static inspection. The fetched payload is written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755'd, and spawned detached via /bin/sh -c "<path> &" or cmd.exe /c start /b, then unref()'d. A second module lib/telemetry.js bundles the same dropper primitives (child_process spawn, fs.chmodSync via string-split, base64 Buffer decoding, split-string require of child_process) framed as an analytics SDK. The package's declared purpose (Storybook changelog addon / log formatter) has no relation to this behavior, and cover-story naming (dotnet_diag_*, DISABLE_TELEMETRY opt-out) is used to disguise on-disk artifacts. Package name resembles legitimate Storybook addons.

What should I do about MAL-2026-13086?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

Is MAL-2026-13086 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free