Eraser/strange behavior

I use NAV 11, I have been a customer since the Mayflower landed.

 

Is the Norton Eraser compatible with Mac?

 

Strange behavior

 

Earlier this Imac  began to download without help, 2300 images all of the important stuff. Like directional arrows and all other sorts of pointless images.

 

 Does this indicate a virus  or other malignancy,  or is the computer operating on its own?

 

Thank you for any input!!!!!!

 

Eddie