Blogs on Google’s blogging system redirect to spam sites.
Spammers are using botnets to mass-create phony blogs on
Google
‘s free
Blogger
system, with the phony entries redirecting to spam sites.
According to research by security company
Websense
, a large botnet is used to surpass the CAPTCHAs used by
Google
in an attempt to prevent automatic registration of blogs. As seen in
similar cases
, the success rate of cracking the CAPTCHA is relatively low (in this case it is believed to be between 8 and 13 per cent), but still high enough for a large botnet to create a significant number of blogs.
Since many spam filters block emails that contain links to sites that are known to spam and/or serve malware, spammers have started to use tricks to hide the URL. One such trick is the use of
Google
‘s “I’m feeling lucking” button, together with a cleverly constructed search, while recently an open redirect in
Google
‘s
AdSense
has been used to trick spam filters into believing a URL is harmless.
By making use of the facility in
Blogger
to have a blog redirect to an entirely different website, spammers have managed to obtain a large number URLs on the
blogspot.com
domain that redirect to their sites. Such URLs occur in many genuine emails and there is no way for a spam filter to decide whether such a URL links to a real blog, other than by following the link and studying the actual website.
Details of the
Websense
researchers’ findings are
here
.
Posted on 25 April 2008 by
Virus Bulletin
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