Blackhat SEO poisoning attacks

Recently , i have reported that Google Image search and Bing Image search leads to malware sites especially a blackhole exploit kit page. The reason behind this attack is SEO Poisoning.

What is SEO?
Search engine optimization (SEO) is a collection of techniques to improve the visibility of a website in a search engine's search results. Some of the techniques used by webmasters in

What is BlackHat SEO?

Black Hat SEO , also known as SEO poisoning, is a illegal-technique used by cyber criminals to make their links appear higher than legitimate results. When a user search for related keywords, the infected links appear in the top of the search results

Hacker use one of the following techniques:

*Creating SEO-friendly fake pages related to poplar search topics on  compromised sites
*Cloak malicious content from sphiders and security researchers.
* Iframe injection

Poisoning Image search Results:

As most of search engines filter and find the text-based seo poisoning attacks, Cyber criminals now poisoning the Image search results instead. 

They hacked legitimate sites and inject malicoius code.  Whenever a person click the Image of compromised site in the search result , it will redirect him to malware sites.  Sophos reports that bing image-search results are being poisoned more than other search engines.