MAL-2026-12591 Malicious code in checkout-select-pos-offer-am (npm)

Malicious package Published
Package
checkout-select-pos-offer-am
Registry
npm

What is MAL-2026-12591?

MAL-2026-12591 is a malicious package in checkout-select-pos-offer-am, published on 5 Aug 2026.

Official description

index.js unconditionally requires ext.js on load, which fetches a platform-specific binary from obfuscated 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 chunked-base64 fallback via *.dl.wel1.ru, writes it to /tmp or %TEMP% under disguised filenames (.cache<hex>, dotnet_diag_<hex>.exe), chmods it to 0755, and detach-spawns it via /bin/sh -c or cmd.exe /c start /b. Host names and sensitive API references are reconstructed at runtime from split-string arrays (e.g. host strings assembled via.join('') and require(&#39;child_&#39; + &#39;process&#39;), fs[&#39;chmod&#39; + &#39;Sync&#39;]) to evade static analysis, and DISABLE_TELEMETRY/ANALYTICS_OPT_OUT env checks are used as cover-story naming. lib/telemetry.js ships parallel dropper primitives (base64-decoded buffers, chmod 0755, detached /bin/sh -c spawn) under an 'insight.node' analytics SDK disguise. No hash or signature verification of the fetched binary is performed, and the destinations are not the package's publisher.

What should I do about MAL-2026-12591?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

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