The driving force behind WHMCSFull claims the project is a protest against WHMCS for allegedly ignoring responsibly disclosed security vulnerabilities.

Standard WHMCS comes with PayPal and a few basic gateways. The "Exclusive" variant adds:

Historically, WHMCS offered two primary ways to acquire the software: (Monthly/Annual payments) and Owned (One-time purchase). The term "Exclusive" in this context usually refers to the Owned License model.

or a specific high-tier package offered by third-party developers

Scanning the file [Insert URL or filename] confirms the presence of obfuscated malicious PHP code (Backdoor/PHP/WebShell).