MAL-2026-12770 Malicious code in devplatform-spa-plugin-location (npm)

On require() of the package, index.js loads vendor.js, which selects a platform-specific payload URL by joining string fragments to reconstruct Cloudflare Worker hostnames (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev), with a DNS-TXT chunked base64 fallback via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under disguised names (e.g. 'dotnet_diag.exe', '.cache_'), chmod 0755, and executed detached via spawn('/bin/sh', ['-c', fp + ' &'], {detached:true}).unref() or spawn('cmd',…). Hostname fragments are array-joined at runtime and a helper suppresses console output, deliberately evading static inspection. The package name resembles a legitimate SPA plugin but the shipped _vendor.js is a dropper granting arbitrary remote code execution on any host that imports the module.

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.