This threat is a supply-chain attack targeting npm packages published by the maintainer polymarketdev (GitHub actor texsellix). Nine packages, including polymarket-auto-trade, were published within a two-minute window and contain identical malicious payloads in their dist/index.js file. The payload wraps legitimate Polymarket CLOB SDK and other libraries to appear functional while exfiltrating Ethereum private keys to a Cloudflare Worker C2 endpoint. The postinstall script detects interactive shells to selectively prompt for private keys or silently steal them from .env files. It creates local persistence files with device and wallet fingerprints and sends stolen keys with device identifiers over HTTPS. The campaign targets developers using LLM-assisted coding workflows and trade automation tools, exploiting trust in these packages.

Any system that installs or runs these malicious packages is considered fully compromised. Ethereum private keys stored or entered on the infected system are exfiltrated to an attacker-controlled server, resulting in loss of control over associated cryptocurrency assets. Because the malware establishes local persistence and fingerprints devices, attackers may maintain ongoing access. The presence of these packages in development environments risks widespread credential theft and financial loss. Removing the package alone does not guarantee full remediation due to potential additional malware installed.

Immediate removal of all affected packages is required. All Ethereum private keys and secrets stored or used on the compromised system must be rotated immediately from a separate, secure environment. Because the malware establishes persistence and may have granted full system control to attackers, a full system compromise should be assumed. Reinstalling the operating system or restoring from a known clean backup is recommended. Developers should verify package provenance carefully and avoid installing untrusted or unknown npm packages, especially those published in rapid succession by the same maintainer. Monitor official advisories for updates.