It’s hard enough getting legit software in general to work on Linux. Even if a virus was written for Ubuntu, it is likely not going to run on Fedora, or Arch, or even downstream/upstream versions of Ubuntu.

Edit: Although thinking about it, Linux terminal commands are pretty universal, so if you manage to execute a script or terminal command as root or sudo then I guess it could apply to multiple distros.

Right-click on the applet (where you want to middle-click), select ‘Applet preferences’ -> ‘Configure’. Change the ‘Middle click action’.