MAL-2026-12745 Malicious code in devplatform-rest-resources-v1 (npm)

On require() of the package, index.js loads bootstrap.js which selects a platform-specific endpoint, fetches an opaque native binary over HTTPS from author-controlled Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) with a DNS-TXT fallback to *.dl.wel1.ru, writes it to /tmp or %TEMP% under disguised names (.cache<rand> on POSIX, dotnet_diag_<rand>.exe on Windows), chmods 0o755 on POSIX, and spawns it detached with output suppressed via spawn("/bin/sh", ["-c", fp+" &"], {detached:true}).unref() (and a cmd equivalent on Windows). The C2 hostnames, fallback DNS domain, and the child_process module name are assembled from array joins (e.g. ["oob-worker.cf102-","baf.work","ers.de","v"].join("") and ['sdk.dl','.wel1.ru'].join("")) to hide indicators from static scanners. Additional cover-story mechanisms include stamp-based execution gating (STAMP_TTL) and honoring DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK env vars while presenting the fetched artifacts as diagnostic/analytics files. No signature verification, no version pinning, and the payload is a bare native executable. Every installer that installs or requires this package receives and executes attacker-controlled code.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.