Many “profile viewer” tools ask you to download a file or complete a survey. That file often contains keyloggers, spyware, or ransomware.
The Illusion of Transparency: Why You Can’t See Who Views Your Facebook Profile how to find profile viewer in facebook
If you want to see how many people are visiting your profile rather than who specifically, you can switch to Facebook Professional Mode. Who views your Facebook profile | Facebook Help Center Many “profile viewer” tools ask you to download