Remove “Attention! 13 viruses detected” Pop-ups, How?

A pop-up box saying “Attention! 13 viruses detected” keeps showing on your screen? Feel really annoy with those pop-ups? Have no idea to get rid of the “Attention! 13 viruses detected” pop-ups?
Please read this post carefully and learn the removal solutions introduced here.

“Attention! 13 viruses detected” is deemed as a fake security alert caused by some kind of malware or viruses that have already infected your computer. If your computer appears the following problems, it is likely to be infected with some kind of infections:

1. Unknown browser extensions, add-on and plug-ins have been installed into your web browser. 
2. Unknown website addresses have been added onto your favorite website folder. 
3. Numerous pop-ups, sponsored links and advertising banners show on almost each web page you are visiting.  
4. Random web page text is turned into hyperlinks.
5. Malicious infections might get access to your PC without asking for any permission.