MAL-2026-12681 Malicious code in delivery-ci-storybook (npm)

On require() of delivery-ci-storybook, index.js loads bridge.js which downloads a platform-specific executable from one of three anonymous Cloudflare Workers subdomains (oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev) whose hostnames are reconstructed at runtime from split string fragments joined with empty separators. If the HTTP fetch fails, a fallback path reassembles base64 chunks from DNS TXT records under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The retrieved bytes are written to /var/tmp or %TEMP% under disguised names (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh -c or cmd /c start. No hash or signature verification is performed and the destinations are not publisher-controlled infrastructure. The fetched executable is attacker-controlled content executed on the installer's host at package require time.

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.