Cashy have a look at
https://www.bleepingcomputer.com/ as they will be able to advise you best.
if you can take a screenshot and post it there or look at their virus removal guides.
Have a look and see if it is one of these:
https://www.bleepingcomputer.com/virus-removal/
You have been infected and need something like malwarebytes to assist after removing it.