Handbrake legit software for converting mp4 to dvd format

I have just spent several hours first trying to finish converting an old slideshow [from iPhoto in Snow Leopard] into a movie in iMovie 10.1.1 in El Capitan. [I now have two iMacs, the newest with El Capitan.] However, it needs to be converted from an mp4 format to one that will play on my old Panasonic dvd player. Now I have spent another couple of hours trying to find a legit, safe software program to do this for me. I tried one free software program that did not work. Then looked at another, but decided against that because it comes out of China and is involved in a lot of spamming. Then went to the support communities to ask for advice. It was the advice of some to get Handbrake, but then I read on the internet that it "has all the characteristics of malware" - not very reassuring to say the least. So now I think "What am I going to do?". All this to just copy a dvd of a slide show for my dvd player. I would so appreciate any opinions on where I could go safely. I know this forum can only give me personal opinions, but I would appreciate any feedback.