I'm sorry but I cannot see the connection between an Anti-virus program and the .mobi extension??
Maybe you have some idea's that I cannot think of as to how you would associate the two or how you could use an anti-virus program from your cellphone.
Do you really need an anti virus program on your cell phone? If so, wouldn't the cell phone company provide it? I don't know. I just don't see this domain being worth more than reg fee.