Much of the time it is simply because the site is still using "http" instead of updating to the more secure "https". That's one cause. That's also the reason you won't see any kind of "locked" indicator/icon along with the url in a browser's location box/field. You will notice that TS uses the new system. But it can require a lot of tedious work in a large site or at least the effort to make the change for a small outfit.
However, when I opened the link in Safari, I had to copy the link into TextEdit to even see that the "http://"! Safari simply displayed "
www.macvideostudio.com/total-video-downloader-mac.html"!Yes the "s" is missing, but why hide the whole format?! Thanks for nothing Apple!
Even if this 'company' includes malware in their apps, it may be nothing more than 'borrowing' your IP address. "What? Me worry?"
However, the missing "s" is an indication, to me, that this is not a professional dev. Looking at the page source I see some (probably) Chinese characters. I suspect it is simply a 'foreign' knock off product.