The npm package 'checkout-mobile-pay-button' version 20.8.3 is a malicious lure package that executes attacker-controlled code upon installation or require. It downloads and runs a platform-specific binary from obfuscated attacker-controlled domains, potentially compromising the host system. The package exports a stub class with no legitimate functionality, serving only to deliver and execute malicious payloads. Systems with this package installed should be considered fully compromised, and secrets on those systems should be rotated immediately.