OPTIONAL: If you have any questions as to whether or not one of your installed programs is trustworthy, use another web browser (either installed on your computer or using another computer) and go to Google's website and type in the name of the questionable program, then click the Search button. If you see a lot of pages reporting "how to remove [name of program]", then chances are you have found the rogue program causing the problem.
5. At this point the program causing your browser to become hijacked should be removed from the system. Next, launch your web browser; do not be alarmed if the scam site appears again; this time you should be able to get inside the browser settings to remove the scam site from your home page.
If you're not sure how to reset the home page for your particular browser, go to Google.com and search for "[name of browser] set homepage" or similar. In this case you can press CTRL + T to open a new tab on the browser to perform the search; if that does not work, then launch another web browser on the computer (if you have one installed). If that doesn't work, then you will have to use another computer to perform the search.
6. Next, go to the browser's add-ons or extensions and disable any add-ons / extensions that you don't recognize. In Firefox (for example), click Tools -> Add-ons, then review both the Extensions and Plugins menus (on the left of the screen) and disable anything that looks suspicious. If in doubt, search Google for the name of the extension / add-on, followed by the name of the browser.
7. You may also want to perform a malware scan of your system. Malwarebytes antimalware is one of my personal favorites for removing malware, and it's free. Tip: don't enable the Pro version of the program if don't intend to pay for it within 30 days, otherwise the program will report itself as being 'unregistered' once the trial expires.
To kill the Tech Support Scam – Call for Support pop-up we will need to close your browser.
Press Command + Option + Escape simultaneously. This will open the open the Force Quit Applications window.
Select Safari, Chrome, Firefox or any other browser in which your are seeing the Tech Support Scam – Call for Support ransomware notification.
Click the button that says “Force Quit“. This will forcefully end your browser program, thus removing the Tech Support Scam – Call for Support browser hijacker.
If you cannot switch from the unresponsive app, press Command + Option + Shift + Esc for three seconds to force it to quit. This key combination tells OS X to force quit the frontmost app.Alternatively, if you are using Safari or any other browser, you can disconnect your Internet, then open the web browser, navigate from the malicious web page, then reconnect to the Internet.