Is my iphone broken and is there a virus on it or is it hacked?

My phone is a iphone 8 and it is fairly new because I got it last year. When I call people, I can hear a echoing sound on the background of the iphone. When I use my phone to search on google, it is extremely slow. Also my battery depletes so fast and i always have to charge it.

Send it back to Apple for repair.

You 've probably got a virus. It would be best to do a clean install of the OS.

Start by removing all apps as some run in the background draining the batteries.

Problems like that can be caused by a corrupted update install.

The first thing to try is a full system reload, the equivalent of formatting a PC and re-installing the operating system…

Do a full backup using itunes.

Then put it in DFU mode while connecting to itunes; it will be fully erased and everything reloaded as if it were brand new.

Then start the activation sequence and select to reload it from a backup, so it gets all you data restored to it.

More info:

If it still does not work, then you need to contact Apple support.
Tell them you have already done the DFU restore, it will skip past a stage with them.