Authentication Popup issue, is this a virus?

[deans86]

Hello, i'm getting the attached symbols on my authenticate screen when my macbook asks me for my admin password. Anybody have a clue what it is and how I stop it? Many thanks!

 

[Weaselboy]

That looks like you have some bad or corrupt system fonts. Have you messed around with fits lately?

Try opening Font Book app and select all the fonts then validate them in the File menu.