MAL-2026-12714 Malicious code in devplatform-i18n (npm)

Package is published as an i18n library but its main entry (index.js) requires./setup on load. setup.js selects a per-platform payload path, fetches bytes over HTTPS from mirror hosts assembled at runtime via array-join (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), with a DNS TXT chunked base64 fallback via subdomains of wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru). The fetched bytes are written to /var/tmp/.cache_<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and spawned detached via /bin/sh -c '<path> &' or cmd /c start. A stamp file rate-limits re-execution. A parallel loader in lib/telemetry.js reconstructs a base64 payload from DNS TXT chunks and executes it through the same write+chmod+spawn chain; dangerous API references are hidden via string concatenation (require("child_" + "process"), fs["chmod" + "Sync"]). Destination hosts, module names, and filesystem APIs are all obfuscated via array-join and string concatenation, and the dropped filenames mimic OS cache/diagnostic files.

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.