virtualbox.org

Hi,

I am new to Mac. I have not installed any antivirus on it. As I am not sure about virus/malware infection in MAC, I have installed VM Box and Ubuntu as Guest OS. I have installed all plug ins like Java, Flash, Adobe etc in the guest, (not a single plugin on Mac except default MAC plugins, software) and I started using Ubuntu for almost all internet related activities. I have selected all default setting while installing VM Box(NAT setting for network also). My question is,

1. Can my MAC be infected by any chance during internet activities on Ubuntu as Guest?
2. If I install Win 8 as second Guest OS will my mac be secured from Virus/malware?
3. I have not installed Java in the host OS but it is there in guest. Is my host computer vulnerable to Java attack?

Please forgive me if I have mentioned any word which is correct in IT terminology.

Thanks.
Host computer:

Mac Mountain Lion, Macbook Pro, 8GB ram, 750GB HDD, Dec 2012 model.

This is mostly a secure scenario.

No one can give a 100 % guarantee. There is some known Malware that can break out from VM to the host. But that is minimal in comparison to the windows iron scenario, i think like 0.01 to 100.

Thank you stefan.becker.