Windows 10, Google Chrome, Yahoo Mail Virus Maybe?

My Yahoo mail is not allowing me to sort it to send it to new folders and then it's deleting them. I'm showing 159 e-mails are in the in-box but it only shows 7 of them and the rest are gone. I don't know for sure that they are being deleted, they just aren't there. I'm not sure what virus it is, if it is one, much less how to kill it. I tried using the security on my system, but it wouldn't do anything. It just said that an error occurred and try again later. Any help would be greatly appreciated.

 

Try transfering your yahoo account to a fresh gmail setup and see what transcribes from there?

 

https://help.yahoo.com/kb/SLN2552.html