MAL-2026-13095 Malicious code in boxy-use-what-changed (npm)

On require() of boxy-use-what-changed, index.js loads ext.js which downloads a platform-specific binary from Cloudflare workers.dev subdomains (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev), with a DNS TXT-record fallback under dl.wel1.ru (sdk.dl.wel1.ru, net.dl.wel1.ru). Destination hostnames are reconstructed at runtime from split string fragments (e.g. ["oob-worker.cf","100-416.worke","rs.dev"].join("")) to evade static string matching. The fetched payload is written to a disguised path in /tmp or %TEMP% (.cache<hex> or dotnet_diag_<hex>.exe), chmod 0o755, and executed detached via cp.spawn("/bin/sh", ["-c", path+" &"], {detached:true}) or the Windows cmd equivalent. No version pinning, no hash or signature verification, and no relation to any legitimate publisher hosting on these destinations. A second file, lib/telemetry.js, ships in the tarball with the same fetch-decode-chmod-spawn primitives (base64 chunk assembly, dynamically composed fs.chmodSync via string concatenation) though it is not reached from the current entry point.