Es-file-explorer-possible-malware-dianxin-folder
forum.xda-developers.com
forum.xda-developers.com
https://www.reddit.com/r/AndroidQuestions/comments/33ditu/di...
https://forums.oneplus.net/threads/low-storage-space.213939/...
http://androidforums.com/threads/dianxin-folder-overtaking-s...
https://home.mcafee.com/virusinfo/virusprofile.aspx?key=4123...
https://www.virustotal.com/en-gb/domain/v.dianxin.com/inform...
OI File Manager seems just fine.
ES and QuickPic tipped me over the edge into just uninstalling everything and using my phone as a phone. Two very good programs that gradually became malware, pushing cloud options onto me, pushing arbitrary notifications when I installed other apps, etcetera.
I now have a very basic CM install with a few OSS F-Droid applications. The phone is used predominantly as a phone and for anything else I go and use a computer with a much better ecosystem.