Black Hat SEO Poisoning is a technique used by cybercriminals to trick search engines, such as Google, Bing, and Yahoo, into ranking a malicious website high in the search engine results page. People land on these sites by entering certain keywords on search engines and clicking on rogue links from the compromised search results. This allows the attackers to have control of web traffic and enables them to lure users on to their infected sites. Cybercriminals have successfully distributed fake antivirus applications (such as Disk Antivirus Professional, MS Removal Tool, and Live Security Platinum) through malicious web pages and use Black hat SEO Poisoning to achieve web traffic.
Black Hat SEO poisoning violates search engines’ terms of service and will result in the website being banned from the search engine and affiliate sites. Web developers may use Black Hat SEO techniques to advertently rank their website higher and gain advertisement profits from several entities. If these Black Hat SEO techniques are discovered, the search engine will no longer list the website within its search results page. However, cybercriminals are not too concerned with having their website banned. Eventually, they know that they will get banned at some point. The goal is to trick as many website visitors as they possibly can into clicking on the rogue links prior to being discovered. Black Hat SEO techniques include:

•Keyword Stuffing

You’ve probably landed on a web page that was “stuffed” with several keywords throughout the site, but nothing much else was present. This practice is called keyword stuffing. Keyword stuffing is used to trick search engine crawlers into thinking that your web page is relevant.
Keywords can also be stuffed between Meta tags. Meta tags reside between the head tag of a Hypertext Markup Language (HTML) document. Web developers use Meta tags to provide a brief description of the website’s purpose.This allows for search engines to identify these websites and rank them appropriately based on the keywords being utilized. However, when used as a Black Hat SEO technique, Meta descriptions are stuffed with keywords that are irrelevant to the actual website.

•Doorway Pages

Doorway pages are “hidden” pages, or fake pages, that a website visitor never sees. However, doorway pages are created to attract search engine crawlers in attempt to have a website rank high on the search engine results page. The fake pages are stuffed with keywords and the end user never sees these web pages because visitors are redirected to the malicious web page.

•Hidden Text

The hidden text technique utilizes keyword stuffing. However, the keywords font color and background color match, making the keywords appear to be invisible.
Another technique to hide text is to use keyword stuffing within HTML comment tags. Legitimate uses of comment tags include web developer documentation, reminders, code explanation, etc. However, as a Black Hat SEO technique, comment tags are used to stuff keywords and maliciously promote a website for higher search engine results rankings.
Keyword stuffing can also be hidden within scripting tags. For example, a cybercriminal can hide content by using the noscript tag. You normally use the noscript tag to alert website visitors that their Internet browsers are not compatible with the script being utilized on the website. As a Black Hat SEO technique, however, the noscript tag is used to stuff keywords and hide them from website visitors. Content can be hidden within other HTML tags, including noframes. Similar to the previous Black Hat SEO techniques, the noframes tag is used to hide keyword inputs in forms. Additionally, keywords can be hidden within Cascading Style Sheets (CSS).
Other Black Hat SEO poisoning techniques exist in addition to the ones mentioned above. You can protect yourself from these attacks by using URL filtering solutions, enable search engine filtering options, and analyze the search results links carefully before clicking on them.