You have an HP printer or HP AIO connected to your network.  When you add your new XPS 8960 to your "private" network, Windows operating system would manage your printer(s) and installing driver(s) automatically.  HP Smart is printer app for HP printer products and would be installed by Microsoft Windows during the driver installation process, similar as Waves Maxx gotten installed with Realtek Audio driver.
Like the title says: Why does my brand new factory-fresh XPS 8960 have an HP Smart app?
XPS 8960, why include "HP Smart"?