Hello, I have installed VirtualBox on my MacBook Air, then installed Windows 10, and finally got a copy of Office 2010 installed. The only reason I did all this was because Office 2016 for Mac doesn't support "slices" in PivotTables (at least the ones my work mates produce on their PC based Excel 2013). I can download the Excel files I need from my corporate Box account, and get them into the Virtual environment through sharing a folder. So... here's the question: Do I need a PC based Antivirus to run if: 1- I never ever, never ever ever never open a browser while in the VirtualBox? I am only using Excel to copy some charts into Powerpoint then bringing them back to the Mac side? 2- If I use the "Edge" explorer in Windows 10 to ONLY go to Box.com, to download the spreadsheet directly instead of downloading on the Mac side and "sharing" to the VirtualBox. No Yahoo, No Google, no mail, nothing else on line. Would I still be at risk? In each case I have the standard Mac firewall running. If I do need an Antivirus, I could get Norton for free from Comcast (my ISP), I should install it in the VirtualBox environment, right? Thanks for the thoughts!!