TeamViewer. It's basically VNC, but with a middleman proxy so you don't need to do any hole punching, it has a single file executable "quick support" download,

TeamViewer. It's basically VNC, but with a middleman proxy so you don't need to do any hole punching, it has a single file executable "quick support" download, and random one-time passwords. Somewhat ironically, it's also what scammers tend to use.