MAL-2026-12913 Malicious code in bnpl-blocks-desktop-bnpl-article-author (npm)

On require, index.js loads _shim.js, which fetches a platform-specific native executable from hardcoded hosts reconstructed at runtime via array .join('') to evade string search: oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev. The fetched bytes are written to /tmp or %TEMP% under cover-story names (dotnet_diag_*.exe, .cache_*), chmodded 0755, and spawned detached via spawn('/bin/sh', ['-c', fp + ' &'], {detached:true}) or spawn('cmd',...). A DNS-over-TXT covert channel provides fallback delivery: dns.resolveTxt is used against c.<domain> and <i>.<domain> under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru; TXT records are base64-decoded, concatenated into an executable buffer, written to disk and spawned. A state file .analytics_state is maintained. The package's declared name ("session management") does not justify fetching or executing native binaries, and none of the destinations are publisher-owned or version-pinned; the delivered bytes are opaque, un-hashed, and mutable at the operators' discretion.