The full offline standalone installer 1.27a2 versions of WC3 which is freely available to download from Blizzard's own servers in any language and for any supported OS, regardless of any Battle.net account, are legitimate to get as long as one uses Blizzard's official Legacy downloader to do so.
For the record, StarCraft 1.15.x and Diablo II 1.14b can be obtained exactly the same way.
I hope that more previous full versions of these games will be made available in the future, in the exact same way.
Heya, love your models and dedication, as it is a tedious thing to do as a fellow modeller but not for WC3, mind if I use a couple of your models/skins for a campaign im currently making.
Btw it will be an actual completed campaign and not one that will be scratched since its a already 50% complete and you would of course receive credit unless you choose not to, ask any questions if you want more info.