Posted by Virus Bulletin on May 17, 2013
'If websites want to include ads, they must make sure they are secure.'
In an open letter to several prominent German websites, Botfrei, the German anti-botnet advisory centre, has defended its advice to users to run advertisement-blocking tools.
In the letter (published in German here), Botfrei's Thorsten Kraft says he understands the websites' wish to make money through advertisements. However, he will not change his stance on ad blockers as long as ad-serving systems remain vulnerable to malware being served.
The letter is a response to explicit requests made by the websites (such as the one at Der Spiegel here) to make exceptions for them in ad-blocking software - saying that if exceptions are not made, they might be forced to put their content behind a paywall.
The request is understandable: it is no secret that online news sites have a hard time getting funds through advertisements, and visitors who don't see the ads aren't interesting for advertisers. It is also understandable that most websites outsource the sale and placement of ads: these require special skills that may not be available among those running the sites themselves.
But by doing so, they implicitly hand control of the content of parts of their websites to a third party. And herein lies the problem: there have been several cases where the third-party services have been compromised, thus infecting many of the sites' visitors through drive-by downloads.
In fact, Kraft lays the real blame at the feet of the ad-serving services, saying that there have been cases where months after a severe vulnerability had been discovered, their services were still "as open as a barn door".
Removing advertisements is not a viable option for most websites. It will thus be interesting to see if many people will follow Botfrei's advice. If they do, it might provide just the incentive needed for ad-serving services to tighten up their security.
Posted on 17 May 2013 by Martijn Grooten
