Ebay – and others – have been caught deploying port scanning on your machine when you visit their website. We’re not talking about scanning your gateway. We’re talking about scanning the very machine that you’re using to visit their website. How is this possible? Well, modern browsers support a technology known as WebRTC that makes it possible to do video conferencing – among others – without installing software. This technology is what enables port scanning to be done by the website. To protect yourself, you should install browser add-ons to disable WebRTC when not in use.
Websites are scanning for open ports on your PC to help fight fraud, but this data also flows into a massive, global tracking database.