The 'claims-payout-offer-domain' npm package (version 35.6.1) includes a malicious component in its index.js that unconditionally loads a _vendor.js script. This script dynamically constructs URLs to Cloudflare Workers hosts to fetch an OS/architecture-specific binary payload over HTTPS. If the primary method fails, a DNS-TXT covert channel fallback retrieves base64-encoded payload chunks from subdomains of dl.wel1.ru. The binary is saved to temporary directories under disguised filenames, made executable, and then executed detached via shell commands. There is no pinning, hash verification, or signature validation of the downloaded payload, and the payload sources are not affiliated with the package publisher, indicating a supply chain compromise or malicious package design.

This behavior allows arbitrary code execution on the host system with the permissions of the user running the Node.js process. The lack of integrity checks and the use of obfuscated, external payload delivery mechanisms increase the risk of persistent and stealthy compromise. This could lead to system takeover, data theft, or further malware deployment.

No official patch or remediation is currently documented for this package version. Users should immediately cease using 'claims-payout-offer-domain' version 35.6.1 and remove it from their environments. Avoid installing or requiring this package until a trusted, verified version is released. Monitor for any unexpected processes or binaries matching the described behavior. Check vendor advisories or trusted security sources for updates on remediation.