User flow spam

I have recently signed up for Google Analytics and have been tracking my company’s site to see how people find us and basically track our users flow.

I’ve noticed that most of our “starting pages” are porn sites and other spam sites.

Is this a problem I can fix via wordpress?

Or are people using my company’s site as a jumping off point to get to sketchy sites? I’m unsure of how this works.

Any advice or information on the topic would be much appreciated!