Google is continuously fighting spam content, links and hackers’ website spam for many years. It improved its technology from time to time to keep spam and malicious content away from Search.
SpamBrain: our most effective solution against spam
With an increasing volume of sophisticated spam being produced every day, SpamBrain’s ability to identify disruptive and malicious behaviors among billions of web pages has allowed us to keep more than 99% of searches spam-free. – Google
Google worked hard to fight low-quality content and link manipulations to get unnatural ranking by violating search quality guidelines.