I have the same problem too! I also have been using my Leagoo Z6 for almost a year now and that DA Brower shows up from nowhere. At first i just constantly uninstall it but then it just wont stop showing itself. In my case though it only appears when i activate the wifi. Without wifi it doesnt show. It causes these annoying problems.
1. It won't allow me to type, my keyboard won't show up.
2. Small ads keeps popping up and eventually the fullscreen ones. This is especially annoying when i'm playing online games. The ads are mostly about mini games which i'm not interested in.
3. Another malware called Android Innovation also tags along.
4. Those ads just popup whenever they like and bothers me in everything i'm doing (surfing the net, texting, literally everything).
5. I tried force stop it or block all of its notifications, but its no use.
6. They add a bunch of weird files in both my phone storage and sd card. Most of the files starts with a (.)
7. I tried searching for it on Google but no result found. I only found this page because i typed Android Innovation instead of DA Brower.
8. Oh almost forgot, it also attacks my Google Chrome. It usually adds 2 new tabs and directs to a page where it tells me i can get mini games.
9. I factory reset my phone lots of times but also no use. It just comes back like it is one of the pre-installed apps.
I'm not rich to buy a new phone so I'll do whatever it takes to get rid of it. Tech stuff isn't really my strong suit but i will try those methods above. Wish me luck! Thank you.