I've had an Xperia z3 d6616 for a little over a year and a half now, and it's battery life suddenly dropped. It went from having a day to a day and a half of battery life with stamina mode (which I was getting just last week) to about 8 hours battery life about 2 days ago. I only really started working it out today, and it's been kind of odd. When I went to check what was using up the battery life, there was no one program using everything up (the largest contributor was the screen at 20%, followed by Pokemon Go at 10%), but the sum of the percentages was only at 51%, meaning that there's a mystery 49%, about half of it, being taken up by who knows what. I figured it was a virus doing all this, which was the only logical solution I could find, so I ran a few scans from Kaspersky and Malwarebytes. Both the scans came up empty, but I tried using some more newly downloaded antivirus programs (Norton, AVG, and Go Security), which ending up calling just about every app I had a virus. I figured it was a false notification, but then I realized a couple weeks ago Malwarebytes said 3 trusted apps (ES File Explorer, Gmail, and Pandora) had a virus. When I uninstalled and reinstalled them back then, they were completely clean, and I left it pretty much without a second thought. I think I may have gotten a trojan a month or so ago, which infected my apps (included some preinstalled apps), and as a consequence is draining my battery life. That's about all I know as of yet, and I'm not 100% sure if it is the cause (although I am still fairly confident it is); does anybody have any suspicions or advice on what it is?