Hackers are using blackhat search engine optimisation (SEO) techniques to poison search engine results. Often this is with the intention of spreading scareware (also known as fake anti-virus attacks) In fact, SEO poisoning is one of the major methods of attack that we are seeing being used by online criminals at the moment. Fraser and Onur in our labs have written an excellent technical paper (PDF) which discusses the problem, and lifts the lid on how the bad guys are using automated kits to do their dirty work for them.”]
Source: https://grahamcluley.com/automated-seo-poisoning-attacks-explained/