In the constantly raging war between Google and content providers eager to force their results to the top it appears that the scammers have found an new back door to improved page rank – PDF files.
To quote IT Security firm Sohpos
It seems that Google implicitly trusts PDFs more than HTML, in the same way that it trusts links on .edu and .gov sites more than those on commercial web pages.
This allows companies to cram ‘tasty’ keywords into PDF and other documents and effectively fool the search engine into thinking that these websites have interesting content.
It also seems that links in these documents receive similar treatment, allowing multiple sites to point to each other and create an impression of a widely referenced site, artificially boosting rankings
Sophos suspects that this technique could be used to distribute malware but, so far, have only seen it in a marketing campaign.
Details of the hack have been provided to Google, so it is only a matter of time before this loophole is closed. In the meantime less scrupulous websites could use this technique to gain a useful boost in ratings…until Google penalizes them for the tactic.
To see the original Sophos article click here.