MAL-2026-17164 Malicious code in building-build (npm)

The package's sole content is index.js, which on load schedules a timer that fetches a hardcoded list of privileged same-origin paths (/admin, /dashboard, /flag, /api/flag, /secret, /admin/flag) and POSTs each response body to /addPost as JSON of the form {content: path + '::' + body}. When bundled into a web application, this abuses the ambient session of whichever authenticated user loads the bundle to read privileged routes and relay the contents to the site's posting endpoint. package.json has empty description, author, and keywords, no exports, and the name 'building-build' bears no relation to the shipped behavior — the package has no library surface and exists only to deliver this payload.

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.