MAL-2026-13060 Malicious code in boxy-maker-legacy (npm)

On require of the package, runtime.js runs a bootstrap routine that downloads a platform-specific binary from obfuscated Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, cf100-416, cf103-070, cf101-adf), writes it to /tmp or %TEMP% under disguised names such as dotnet_diag<hex>.exe and.cache_<hex>, chmod 0755, and detach-executes it via /bin/sh -c or cmd /c start. Destination hostnames are assembled at runtime by joining fragmented string arrays (e.g. ["oob-worker",".cf99-","9b3.","work","ers.","dev"].join("")) to defeat static string matching. If HTTPS mirrors fail, the code walks DNS TXT records under *.dl.wel1.ru — first c.<domain> for a chunk count, then 0.<domain>, 1.<domain>,… — concatenating base64 fragments to reconstruct the executable payload out-of-band. The package's stated purpose is a trivial BoxyMakerLegacy class with no legitimate need for platform-specific native binaries, remote binary fetches, throwaway workers.dev hosts, disguised staging filenames, or DNS-TXT payload delivery. The behavior fires automatically on import, giving whoever published the package arbitrary code execution on the installer's machine.