InformationWeek > Parry Aftab > Tips On Spotting A Spoofed Link > January 26, 2004

InformationWeek > Parry Aftab > Tips On Spotting A Spoofed Link > January 26, 2004

Here are some tips from an Internet service provider, eBay, and Citibank on ways to avoid being phished.

Citibank Tips
Citibank warns its customers to check the security certificate for any site to which they're linked.

If the name doesn't match the company owning the site, you shouldn't trust the link. It also recognizes that not all certificates are held in a name recognized by consumers accessing the site, but the bank informs its customers that all security certificates for Citibank's sites are held in its "Citibank" name.

Since not all security certificate issuers police similar-sounding "brand-related" names when issuing their certificates, knowing the exact name of the security-certificate holder is key to authenticating the page. All sites should disclose the correct security-certificate holder name at their sites.

EBay Tips
EBay teaches its members how to spot a fake eBay URL by checking the browser Web-address window. (Although, given the Microsoft Internet Explorer vulnerability that permits the URL appearance in the browser window to be spoofed, this tip may be ineffective for IE users.)

Here's how to be sure you're on an eBay page: Before signing in, check the Web address in your browser. If you click on a link in an E-mail, verify that the Web address in your browser is the same as the address shown in the E-mail.

The Web address of most eBay sign-in pages begins with http://signin.ebay.com/. Never type your eBay user ID and password into a Web page that doesn't have ".ebay.com" immediately before the first forward slash (/)."

Examples of real eBay addresses:
http://cgi3.ebay.com/
http://arribada.ebay.com/

Examples of fake eBay addresses:
http://signin.ebay.com@10.19.32.4/
http://signin-ebay.com/

Advice From Those In The Field
I sought the assistance of members of the Internet Society's IETF list in trying to come up with better tips on avoiding phishing and spoofing schemes.

Dean Anderson, who owns and runs an ISP in Boston, explained the basics best, so I want to share his tips with you.

EBay, the FTC, Citibank, and consumer-advocacy groups advise to make sure you're using a secure server connection. Dean comments on the wisdom of that tip and holes that can be exploited by the con artists. "When you connect to a secure Web site, you can examine the SSL Certificate for the site, usually by clicking on the 'lock' symbol on many browsers," he says. "People should learn how to do this and make it a habit of doing so when they connect to secure sites, so they recognize when something changes.

"Unfortunately, like other components of scams, the certificate might have a similar-sounding name. You think you've got (e.g., PayPal.com), but you got paypal-business.com. The certificate (we assume for argument) really does belong to an entity called paypal-business.com, but is paypal-business.com the same as PayPal? You don't know.

"The best thing to do is start from (e.g.) paypal.com from your account statement, etc., and examine the site certificate. Then you have a good chance that it's not spoofed. But it is only a chance, as it could still be spoofed in various ways. There are lots of scenarios for this, but here's one: Your computer could be infected with a virus which installed a Web proxy, then the attacker sends you a message to go update your stuff. You type in paypal.com, but your infected browser goes to the fake site instead. When you try to view the certificate, your infected browser shows you the real certificate information. You can't easily know this didn't happen. But examining the certificate is a good practice.

"So there are things to do that will make the con artist's job harder, but you can't make it impossible to be conned. Hopefully, the police will be able to track down the con artists, and by doing so, will deter others. "There's no perfect system, so we can't give any assurances that there is a perfect system. Nor is the case that if you do or don't do certain things, you can't be victimized. The best we can do is tell people to use their common sense, so they aren't victimized by the lowest grade of con artists."

Amen!