Does the N73 Europe site version the same as the one preloaded in Asian phones?
Anti Virus
You can compare them. Go to support pages and see which one are on each site.
And before you worry about any antivirus stuff, read this:
http://3lib.ukonline.co.uk/viruses.htm
Note also, that there has not been any single virus reports on the N73 or any S60 3rd Edition based phone for as long as they've been available.
All the mobile malware (malicious apps) I've heard of, have been for earlier versions of S60, and they do not install or run on S60 3rd Edition.