MAL-2026-12543
Dashboard / Malicious Package / MAL-2026-12543
MAL-2026-12543
Summary: Malicious code in checkout-base-analytics-data (npm)
Details: Source: amazon-inspector (a6130d2e85aedac754a5a7f0d31a255c2f45d702484e6a81df50ca4c326395aa) On require of the package's main (index.js), the hidden _polyfill.js runs a bootstrap routine that selects a platform-specific asset path, fetches an unverified binary over HTTPS from hostnames assembled at runtime via string-array concatenation (oob-worker.cf101-adf.workers.dev and sibling *.workers.dev endpoints, with a DNS-TXT chunked fallback via *.wel1.ru subdomains including sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru), writes the bytes to /var/tmp or %TEMP% under disguised names such as.cache_<hex> and dotnet_diag_<hex>.exe, chmods the file to 0755, and spawns it detached via /bin/sh or cmd. Endpoint hostnames are split into fragments and reassembled with Array.join to defeat static URL/domain matching, and index.js loads _polyfill unconditionally inside a try/catch so import failure is silenced. The package's declared purpose (a generic 'analytics data runtime support module') and empty dependency list are inconsistent with any legitimate need for a hidden native-binary loader fetching from unrelated *.workers.dev hosts.
Affected packages
Package
Name: checkout-base-analytics-data
Purl: pkg:npm/checkout-base-analytics-data
Affected ranges
Type: N/A
Events:
