If you're on a PC/Laptop, run an anti-virus and make sure your system is clean. Afterward, install a browser plugin to prevent URL redirects and consider an ad-blocker as well.
If you're on a phone, all I'll say is good luck, if its invasive behavior, my first thought immediately goes to factory resetting the device. Alternatively you can try a different browser app.
Either way it's definitely on your end, generally none of us experience these issues, so it's something with your system causing it.