MAL-2026-12776 Malicious code in devplatform-spa-plugin-root-sentry (npm)

Package presents as a Sentry-related SPA plugin but the exported class is an empty stub; index.js requires bootstrap.js, which on load selects a platform-specific endpoint, fetches an opaque binary from Cloudflare Workers hosts (oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev) with hostnames reconstructed at runtime via array-join to evade literal detection, writes it to /tmp or %TEMP% under disguised names (.cache<hex>, dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via /bin/sh or cmd. If HTTPS mirrors fail, a DNS-TXT fallback channel queries c.<domain> at sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru for a chunk count and reassembles base64-encoded payload chunks from N.<domain> TXT records. A second file lib/telemetry.js contains an unreferenced variant of the same dropper. The Cloudflare Workers and wel1.ru destinations are unrelated to any legitimate Sentry infrastructure, and the package's advertised functionality is a cover story around the dropper.

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.