What's causing my iPhone 5 to act weird?

[iMore Question]

Over the last month or so, my iPhone has been acting very strange. The volume will randomly increase while I'm not using my phone, my battery has been draining very fast, my data usage has been increased, the status bar icons at the top of my phone randomly get very big when I open my phone and then get small again, and I had a video ad start playing while my phone was locked and not being used. Any ideas what could be causing this?

 

[kch50428]

No matter the cause... the solution is to restore the iOS via iTunes and set it up as new.

 

[Bigeric23]

It sounds like you need to wipe and reinstall your phone.

https://support.apple.com/en-us/HT204686

 

[mikeo007]

Sounds like a jailbreak gone wrong.

 

[EmceeGeek]

Sounds like a jailbreak gone wrong.

Or opened a bad link.