It's because of the .exe or .dll files depending on your antivirus. Tons of people use SMBX and as long as you've downloaded it from a reliable source you're definitely okay
We can guarantee you that SMBX can not harm your computer as long as its from the official smbx page, do not worry , what program is saying this anyway?
Smbx cant harm your computer , 1.3 , 2.0 and 38A they can't do it but 38A can appear as dangerous file to your antivirus system but it isn't so there is nothing to worry about.