MAL-2026-13639 Malicious code in sme-rko-finance-front-operations-income (npm)

On require of the package, compat.js reconstructs attacker-controlled hostnames via array split-and-join obfuscation (oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev, and sdk/ext/pkg/net.dl.wel1.ru), downloads a platform-specific native executable over HTTPS, writes it to /var/tmp under a hidden dotfile name on Unix or to the Windows temp directory as dotnet_diag<hex>.exe, chmods it to 0755, and spawns it detached via /bin/sh -c or cmd /c start. A fallback retrieval path resolves DNS TXT records at c.<domain> and N.<domain>, base64-decodes and reassembles the chunks into the same executable blob, and writes it to disk for execution — a covert delivery channel that bypasses HTTPS-based network filtering. The package is advertised as a monitoring/observability SDK but ships no functionality matching that purpose; the sole import-time effect is dropping and running an opaque author-controlled binary. Hostname obfuscation via.join(''), masquerade filenames imitating.NET diagnostics tooling, detached spawn, and a DNS-TXT covert channel are consistent with a supply-chain remote code execution dropper.