Original URL: http://www.theregister.co.uk/2008/12/23/open_redirect/
Scareware mongers hitch free ride on Microsoft.com and others
Attack of the open redirects
Miscreants are exploiting weaknesses in more than one million webpages operated by the federal government, media companies, and even Microsoft to trick unwitting visitors into installing harmful software that takes over their computers.
A Google search conducted by the folks at the CyberCrime & Doing Time blog showed that the web is littered with more than one million links pointing to a single rogue domain. While the links appear to point to trusted domains, people who click on them are taken to a malicious website that claims they need to install security software or offers to stream video.
The so-called open-redirect exploits are the result of webmasters at microsoft.com, nbcsandiego.com, cftc.gov, and hundreds of other sites who fail to follow best practices for their domains, which call for sites to employ blacklists - or better yet, whitelists - that control the sites that can be redirected from the host domain. You can learn a lot more about the problem here (PDF).
The attacks can be especially useful in tricking less-sophisticated users to install software. Many of the Microsoft links, for example, appear to relate to an Internet Explorer download, so users are already prepared to install software on their machines. However, the Microsoft links redirect users to a site that runs a fake computer scan that purports to find dangerous malware, then offers a rogue "anti-virus program" for users to run.
Other exploited websites offer video streaming, so visitors may not be surprised when they're told they need to install a new codec - and that's exactly what happens.
The perpetrators of this scam have spent countless hours making it work. They have planted comments all over the web that cause search queries such as "download fruityloops 6 free" (and many relating to porn) to return high-ranking results that point to popular sites that are vulnerable to the exploit.
While some sites such as irs.gov appear to have fixed the problem, microsoft.com remained wide open at time of writing. Microsoft representatives weren't immediately available for comment. We'll be sure to update this story - if they respond to our request for comment. ®
A few hours after this article was published, the Microsoft links no longer worked. For the record, Microsoft reps never did get back to us.