Once the user has discovered this is the case, they will attempt to uninstall the application. While it may appear it was removed, the user will soon enough discover this application is still in place, running in the background, needlessly hogging resources. The only reason this is not an actual virus is that it is not actually harming the system beyond soaking up power and CPU time from the user.
This may work for other versions of OSX, but since Mac changes many things with every new release, I can only vouchsafe this is a solution for removal of the Buffalo NASNavigator2 application from OSX Lion.
Before doing this, be sure you have backed up your system, just in case!
1- Open a Terminal. To do so, launch the Terminal application from /Applications/Utilities
2- Type in:
sudo find / -name 'NAS*' -print
You will be prompted for a password after issuing a command prefixed with sudo. Simply enter in the same password you would normally use when running "Software Update..."
3- You should then see the location of the application:
sudo rm -rf /Library/PrivilegedHelperTools/NasNavigator2.app