It doesn't seem appropriate to exchange Blizzard's work directly between individuals. Instead, I'll give you an ftp link to download StarCraft demo. Blizzard ftp hub was closed in the past, but downloading ftp file is still valid, so it's a StarCraft demo file that's legal and available as an official route. ftp.blizzard.com/pub/starcraft/demos/SCDemo.exe

Or if you need a full game, you can download classic StarCraft for free on Battle.net. But StarCraft demo has its own campaign, so if you want to play the campaign, it's also worth playing the demo.