MAL-2026-12928 Malicious code in bnpl-blocks-desktop-bnpl-image-plus-text (npm)

Requiring this package loads shim.js, which selects a per-platform payload path and fetches an unpinned, unsigned binary from one of three anonymous Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev) at endpoints /pkg/package.exe, /pkg/package-arm64, and /pkg/loader_mac. The downloaded bytes are written to /tmp or %TEMP% under disguised names (dotnet_diag<hex>.exe,.cache_<hex>), chmod 0755, and spawned detached via /bin/sh -c or cmd. If HTTPS fetch fails, _shim.js falls back to DNS TXT smuggling: it resolves a counter TXT record at c.<domain> and then iteratively resolves 0.<domain>..N.<domain> TXT records under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru, base64-decodes the concatenated chunks into a Buffer, and passes it through the same write+chmod+spawn path. Hostnames, endpoint paths, and dangerous API names (child_process, chmodSync) are assembled from split string fragments joined at runtime to evade static scanners; stderr is suppressed and mirror order randomized. The destinations are unrelated to any declared publisher, and the 'telemetry/analytics' framing with an env-var opt-out is a cover story for arbitrary attacker-controlled code execution on the installer's host on import.