MAL-2026-12998 Malicious code in bnpl-blocks-mobile-bnpl-news-cards (npm)

The package's index.js loads _runtime.js on require, which selects a platform-specific asset, fetches an opaque binary over HTTPS from author-controlled Cloudflare Workers hosts (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT fallback channel over sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to /tmp or %TEMP% under cover-story names (.cache_<hex>, dotnet_diag_<hex>.exe, stamp file .analytics_state), chmod 0755, and spawned detached via /bin/sh -c "<path> &" on POSIX or cmd.exe /c start /b on Windows. Destination hostnames and discovery domains are assembled at runtime by Array.join('') on split fragments (e.g., ["oob-wor","ker.cf102-baf.workers.de","v"].join(""), ['sdk.dl.w','el1.r','u'].join('')) to defeat static string scanners. No hash or signature verification is performed on the fetched payload, and the package advertises itself as a trivial mobile SDK unrelated to any of this behavior.