MAL-2026-12152 Malicious code in bigops-auth-provider-interceptor (npm)

On require, bigops-auth-provider-interceptor loads init.js, which reconstructs destination hostnames via string-split/join (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, and fallback sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru), selects a platform-specific binary for Linux/macOS/Windows, downloads it over HTTPS with a DNS-TXT chunked-base64 fallback channel, writes it to /var/tmp/.cache<rand> or %TEMP%\dotnet_diag_<rand>.exe, sets mode 0755, and spawns it detached via /bin/sh -c or cmd. lib/telemetry.js ships a second copy of the same download-decode-chmod-spawn chain with additional string concatenation obfuscation on the child_process require and chmod call. The hostnames are unrelated to the package's declared purpose, no version pin or hash verification is performed, the binary is staged to a hidden dot-file or a filename impersonating a Microsoft.NET diagnostic tool, and execution is detached to survive the installing process. This fires on any require of the package.