MAL-2026-10928 Malicious code in upjsma (npm)

The package's main entry is a browser-only IIFE that, when bundled into a web page, overlays a full-screen mask, injects a fullscreen iframe, and navigates the host page to the hardcoded remote URL https://mfmz.jfcacf.cn/H.html?c=0gjr. There are no install/preinstall/postinstall lifecycle hooks and no Node-side effects; requiring it in Node throws on document. Installing or requiring this package does not by itself run code that exfiltrates data, executes remote code, or persists on the developer's machine, so no direct installer-side attack fingerprint is present. The harm surface is end-users of any web application that bundles this module: they are silently redirected to an off-site page under a third-party domain. The package's name and empty description give no indication of this redirect behavior.

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.