Could it be "Magix PC Check" from Download.com?

I can't seem to find any software by the name of "Majic PC Check" . But I do find a similar sounding name, which is offered (free) at Download.com. Magix PC Check. (No "j" or "c") The executable you referenced does belong to this software.

As you can see by reading the description it's free.
http://download.cnet.com/Magix-PC-Check-Tuning-Free/3000-18512_4-75181588.html

As Mark said, CNET does not sell software. You could try clicking on "Direct Download Link" just UNDER where you see the green "Download Now" button. If the smartscreen filter continues to give you a warning, I would heed the warning. And steer clear of it. But that's just my opinion.

I see it's described as having the ability to "clean and tweak your system". You may be better off letting a (FREE) program such as CCleaner do the cleaning. And leave the "tweaking" behind. happy

Carol