Install an adblocker on Safari - uBlock Origin
uBlock Origin is an independant ad-blocker relying on a currated list of servers. It prevents your browser from connecting to these servers to serve you ads. We recommand it over AdBlock Plus which allows certain ads according to its "Acceptable Ads program".
To install uBlock Origin on Firefox, visit this link.
Click "Install Now" and "Install".
Restart Safari and uBlock Origin will be running