MAL-2026-13272 Malicious code in devplatform-vite-plugin-external (npm)

The package's main entry (index.js) unconditionally requires./setup on load. setup.js selects an OS/arch-specific endpoint and downloads a binary from a rotating list of Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev) whose hostnames are assembled via array-join string splitting to evade static analysis, with a DNS-TXT chunked fallback across sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to a temp path under a disguised name ('dotnet_diag_<tag>.exe' on Windows or '.cache_<tag>' on POSIX), chmod 0755, and spawned detached via cmd.exe /c start /b or /bin/sh -c "fp &". There is no hash or signature verification of the downloaded payload; the source hosts are attacker-controlled infrastructure unrelated to the package's stated Vite-plugin purpose. Execution is suppressed by DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK environment variables and cached via a marker file with a ~21329s TTL, framing the behavior as telemetry while dropping and running an opaque binary. Any consumer that requires or imports this package triggers full-host code execution under attacker control.

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.