MAL-2026-13539 Malicious code in delivery-ci-codeceptjs (npm)

On require of the package's main entry, _helpers.js runs a setup() routine that selects a platform-specific payload path via a _DL_MAP table and downloads an opaque native binary from Cloudflare Workers subdomains whose hostnames are assembled by joining split string fragments (e.g. ["oob-worker.cf103-070.wo","rke","rs",".dev"].join("")), with a DNS-TXT chunked fallback that reassembles a base64 payload from numbered TXT records under *.wel1.ru subdomains (sdk./ext./pkg./net.dl.wel1.ru). The downloaded bytes are written to /var/tmp/.cache_<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and spawned detached via spawn("/bin/sh", ["-c", fp + " &"], {detached:true}) or cmd /c start /b. The package advertises a trivial no-op class and ships no native source consistent with the download; the hostnames are unrelated to the declared purpose, there is no version pinning or hash/signature verification, and the destination assembly and DNS-TXT fallback are structured to evade static string scanners. The staging paths use hidden dotfile / diagnostic-lookalike names to blend with normal temp-file activity.