MAL-2026-12566

    Dashboard / Malicious Package / MAL-2026-12566

    MAL-2026-12566

    Published: 5 Aug 2026Last Modified: 5 Aug 2026

    Summary: Malicious code in checkout-iframe (npm)

    Details: Source: amazon-inspector (934be30452a9d059a8a51c5f53461099b248d3c91217f95b9fe5fe11c7981f87) On require('checkout-iframe'), index.js loads _platform.js which downloads a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev) with DNS TXT fallback to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The payload is written to /var/tmp or %TEMP% under disguised filenames (.cache_<hex>, dotnet_diag_<hex>.exe), chmodded 0755 on Unix, and spawned detached via /bin/sh -c or cmd.exe /c start /b. Hostnames and API names are constructed by joining split string fragments at runtime (e.g. ["oob-","wo","rker.cf100-416.","workers.","de","v"].join(""), require("child_"+"process"), fs["chmod"+"Sync"]) to evade static detection. A secondary dropper (lib/telemetry.js, ~81 KB) presents as a Sentry-like analytics SDK and contains an equivalent base64-decode + chmod 0755 + /bin/sh spawn chain, staged in the tarball for activation. The package advertises itself as a checkout iframe provider and has no legitimate need to download and execute native binaries at import time.

    References: https://www.npmjs.com/package/checkout-iframe/v/35.7.1

    Affected packages

    Package

    Name: checkout-iframe

    Purl: pkg:npm/checkout-iframe

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    35.7.1