MAL-2026-12577

    Dashboard / Malicious Package / MAL-2026-12577

    MAL-2026-12577

    Published: 5 Aug 2026Last Modified: 5 Aug 2026

    Summary: Malicious code in checkout-mobile-legal (npm)

    Details: Source: amazon-inspector (5c9d5aebe1a3868e44878f382e7dfd21bcbebf8767f3ff0890b2d6330726f945) On any require/import of this package, index.js loads _init.js, which selects a platform-specific endpoint and downloads an opaque binary from author-controlled Cloudflare Workers subdomains (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev). The hostnames are assembled at runtime by joining string fragments (e.g., ["oob-worker.cf100-416",".work","ers.","dev"].join("")) to evade static inspection. The fetched bytes are written to /var/tmp (or %TEMP%) under disguised names (dotnet_diag_<uid>.exe on Windows,.cache_<uid> on POSIX), chmodded 0755, and executed detached via cp.spawn("/bin/sh", ["-c",...]) or cmd.exe with no hash, signature, or publisher verification. A DNS-TXT fallback under *.dl.wel1.ru subdomains (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) reassembles a base64-encoded payload from TXT records and executes it when HTTPS retrieval fails, a covert channel intended to bypass egress HTTP filtering. A marker file.analytics_state and cover-story naming ("analytics SDK", dotnet_diag) present the code as telemetry, but the behavior is an unverified remote-code-execution dropper. Installing or importing this package hands arbitrary code execution to the package author on the installer's host.

    Affected packages

    Package

    Name: checkout-mobile-legal

    Purl: pkg:npm/checkout-mobile-legal

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    35.8.8
    MAL-2026-12577 | CVE-DB