This is a follow up to the numbers I presented in Part I, which discussed malicious spam pages in Google results and the malicious that sites they redirect to.

Google warnings

The number of spam pages which are flagged by Google represent only about 44% of all spam identified by Zscaler. If we look at spam pages redirecting to a malware, 57% are flagged. These numbers are about the same as what we saw in March 2010 (53% flagged).

52% of the malicious spam links are flagged by Google

Distributions of spam links per page

Spammers are still able to elevate their links to the first page of search results. However, compared to March 2010, there are fewer spam links on the first page than there used to be.

Number of spam links on each result page in Google

In general, more search terms contain Blackhat SEO spam links, but there are fewer such links per search, when compared to March 2010.

Number of spam links per poisoned search

Overall, Google’s Blackhat spam SEO situation has improved: there are fewer spam links on the first page and fewer search terms had more than 50% of links returned as malicious. However, Google still struggles to clean their index, or at least to warn users about real threats.

– Julien

(Zscaler Research)