Sophos, a computer security company has done an excellent job by successfully handling a case of Google’s spam search, which come under cloaking technique. Sophos figured out spam links of cloaked pdfs from Google.

The case deals with cloaking techniques, which guides the user to suspicious websites. This technique is against the Google’s guidelines because the webpage content presented to the end users is completely different if same requested by Googlebot. It was carried out through hundreds of thousands of cloaked PDF documents.

Sophos had conveyed the effect, to Google, but due to the absence of Google’s findings, it has decided to publish this information. The company also said that, this method works fine for spammers, because “Google totally trust PDFs rather than HTML”. It also added, the spammers/hackers insert links to PDF or add new PDF by hacking the sites, so that, the user will be landing into some spam sites.

The firm has successfully found a large set of similar documents in a highly compromised websites. Based on the number of high intense keywords, the PDFs with the links redirects to other websites. Any user if clicked on the PDF, will be landing into irrelevant documents, not the actual PDFs.