A few days ago in a blog entry I touched upon how search engine gamers had been able to use trusted domains and the 302 redirect trick to fool search engines into giving them higher rankings. That window of opportunity is all but closed now, but scammers still use the redirect hack to aid them in their phishing expeditions. They are able to foist their tricks on their unsuspecting victims using two main avenues consisting of spam emails and spam posts.
Suppose you receive an email with the following embedded URL:
Would you click on this email? Most likely not, and nor will many others. You just can't tell who that weird URL belongs to, so you would skip over it. Now consider the following URLs:
Notice how the URLs indicate domains from Google, AOL, and eBay. Some people may still be skeptical about clicking, but others may not be so paranoid. After all those domains emanate from highly trusted sources. The URLs have some encrypted data, but we are all accustomed to seeing long URLs on various sites, and might attribute that to strong security.
This is no trick. Those pages are indeed legitimate pages from well-known sites. But they are specially crafted pages to redirect users to other destinations. They were most likely designed to be used by their respective sites themselves and for other legitimate uses from the outside. But in this case they were hijacked to gain users' confidence prompting them to dutifully click on them. For these samples, users are safely redirected to example.com, but they could have been redirected to a wicked phishing site instead.
Phishers also post the same types of links on various online boards, article sites, or other user submission areas, and they can gain users' trust just the same. Why wouldn't these links be automatically filtered by email servers or web sites? For the same reason average users see no threat in them. Filters might block or distort links they do not recognize, but many may give these links a free pass, convinced that they are from highly trusted sites and are therefore innocuous.
Some well-known sites have started to take defensive measures to foil these types of redirect tricks, but abuse-ready redirect pages still abound. So the next time you come across these types of links in a spam email or on a site, think twice before clicking on them. They may just be the bait-and-switch kind.