How can you get rid of this symbol completely?

It shows up every now and then and when I restart it is gone until I open netflix. If this is malware, how can I get rid of it completely

To do this, you would first have to find out where that is going.

It's best to do a virus scan and then use adwcleaner to clean your browser.

You can find Adwcleaner for free online, but please do not download it from Chip.de or similar sites.

I recommend ESET or Malwarebytes as a virus program