The npm package @wagni_bot/polygon-sdk is a malicious package impersonating the Polygon blockchain SDK. Its postinstall.js script runs automatically on installation and scans the user's directories for wallet keystores, private keys, seed phrases, and other sensitive credentials. It exfiltrates these secrets along with some environment variables to a hardcoded attacker-controlled IP address. The package exports no legitimate functionality and exists solely to steal credentials from developers working with blockchain wallets.