MAL-2026-12352 Malicious code in checkout-mobile-pay-button (npm)

[email protected] is a lure package: its name and README describe a 'mobile pay button platform adapter', but index.js unconditionally require()'s loader.js on load. loader.js reconstructs attacker-controlled hostnames at runtime via string-split/join obfuscation (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), downloads a platform-specific binary via https.get, writes it to /tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnet_diag<hex>.exe on Windows), chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe with.unref(). A DNS TXT covert channel over tin.dl.well1.site / tina.dl.well1.site / ldr.dl.well1.site / win.dl.well1.site (c.<domain> chunk-count then i.<domain> base64 chunks) provides a fallback delivery path when the workers.dev origins fail. The exported CheckoutMobilePayButton class is a stub with no real functionality; the package's only effect on install/require is fetching and executing opaque attacker-controlled bytes on the installer's host.

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.