Because CursorFX is discontinued, legitimate unused keys sell for as little as $3–$10 on secondary markets. Search for "Stardock CursorFX license key" on trusted platforms. This is legal, safe, and supports the original creators (indirectly).
The term is frequently used by sites claiming to offer "pro" features for free. However, it is vital to distinguish between a genuine promotion and a security risk. The Risks of "Free" Product Keys cursorfx 403 product key exclusive
A rumor persists that Stardock issued a handful of to beta testers of version 403. These keys were not locked to a specific machine. To date, no verified copy of such a key has ever been published online. Searching for it is largely a goose chase. Because CursorFX is discontinued