Samsung Galaxy SIII - took a screenshot by itself.

[AC Question]

My phone was sitting down, charging. I did not touch it, nothing touched it. Just took a screenshot by itself.
I am concerned I may have a virus or was hacked..
So, these are the apps I have on my phone. I really need to delete all the ones I don't use anymore, since going through the "All" section of my phone's google play store.. there's a lot I don't use.
Do any of these need to be deleted?
Or do I need to factory reset my phone? ):

Apps are:
Blakery Blitz
DU Battery Saver & Fast Charge
DragonSoul
Shipwreck Volcano Peril Island
5miles: Local buy & Sell stuff
Joy Rewards - Free gift cards
Text Free
Goth Fonts
OldEng Fonts
Fonts for FlipFont 50 written
Where's my droid
ShutApp - Real Battery Saver
Rooster Teeth
Walgreens
Walmart
Hiya - Caller ID & Block
KSBY
The Weaver
Reddit is fun (unofficial)
Straight Talk My Account
Vons
Relax Melodies
The weather channel
Etsy
MangaZoo
Photo Wonder
Go Keyboard, Cool Neon Theme
Wikia: elder Scrolls
Halloween night keyboard
Home - Design and decor shopping
Screenshot snap free
Go Keyboard - Emoji, sticker
Amazon shopping
Panel App
Twitter
myVegas
Messanger
Zillow
Lucktastic
Wish
Pinterest
Safeway
Duolingo
Tumblr
Facebook
Google
Gmail
Chrome
GooglePlay Books
Samsung push service
Google play music
Google talk back
Google play games
Google+
YouTube
Maps
Google play newsstand
Google play movies & tv
Hangouts
Google text-to-speech
Google drive
Whisper
Skype
Netflix
Zedge
Pandora
Google street view
Voice search
Group play
Samsung music
Samsung link