Hey all. I run ubuntu as my main OS, in which i run windows XP as a virtual machine.(my work requires a few windows programs that i can't seem to get away from). my virtual windows uses NAT to access the internet through my computers wireless NIC.

my question is should i be concerned about security on my virtual machine? should i install antivirus / firewall / etc... on the virtual machine? if the vm is connect to the internet through NAT, that means it doesn't have its own ip address...so i can't figure out how to even ping the vm. is it possible for an attacker to target my vm? coudln't someone nmap and exploit my vm? the fact that its using NAT makes me unsure.

thanks for any help, much appreciated