The Apple Macintosh has been seen by its users as a safe regular-computer (desktop / laptop) platform mainly because it didn’t have as much of a foothold as the MS-DOS / Windows platform. Now this platform is starting to appeal to malware authors due to the fact that more people are heading towards it as a regular-computer option along with the fact that Microsoft has been continually hardening the Windows platform.
Of course, don’t follow through with the prompts to call these numbers or download the software because this involves activities like malware downloads or paying exorbitant fees to dodgy overseas-based businesses. But what do you do to close these nag screens?
On the Macintosh, you would have to kill the browser session by using the Force Quit routine. The best way IMHO to do this is to press Command+Option+Shift+ESC together if the browser has the foreground. You can also press Command+Option+ESC to bring up the Force Quit menu and use the mouse or trackpad to select the application to stop. The reason I suggest using the keyboard shortcuts is because some of the nuisance dialog boxes can effectively “take over” the pointing device.
iOS users can stop the browser by double-clicking the Home button and swiping the window representing the troublesome app to kill that app.
On both platforms, you clear out the browser cache and history to stop the fake tech-support Website cropping up. This is more important for the iOS platform because if you open up Safari, it will come up with the last-opened Website. For the OS X implementation, you click the “Clear History” option in the “History” menu, which also clears the cache. For the iOS implementation, you go to the Safari option in the Settings app and then tap the Clear History button to stop it from reopening.