New DNS Technology Flags Bad Guys Before They Act

A new technology developed by DNSstuff could help detect online fraud before it actually occurs, Dark Reading has learned.

The technology is a method for determining a remote user's DNS settings, just as a Website can glean a visitor's IP address, browser version, and other coordinates. Using these settings, a Web server could determine whether a requestor is a cybercriminal, bot, or a legitimate user -- before allowing access to the site.

DNSstuff has filed for a patent for the technology, and the company hopes to rally support to develop products that use this method of detecting DNS settings and matching them to known malicious or infected DNS servers.

"When you connect to Amazon.com, they know your IP address, your browser version, Java version, and OS version. They don't know your DNS settings," says Paul Parisi, CTO for DNSstuff. "Our patent focuses on greater security and better understanding of where traffic is coming from and how it's controlled."

DNSstuff officials say the technology would let Website operators detect suspicious activity before it actually occurs: A visitor using three different DNS servers during three consecutive visits would raise a red flag, for example.

A bad guy can "own" a DNS server that sends a clueless user to a phishing site instead of the real site he requested, for instance. "I could basically direct any domain name you enter to any location I desire. [If] I observe that users use a certain Website frequently... I build a phishing version of that site. I then edit the DNS and you end up going there," Parisi says. "What’s more, if I own it, then I can turn those changes on and off at will, making it more difficult to detect."

Parisi says the concept of checking DNS reputation has never really gotten off the ground because there hadn't been a way to collect the client's DNS information. Meanwhile, users' machines could be pointing to compromised DNS servers without their knowledge. That's where DNSstuff's new technology would come in.

"If your DNS setting changed to a different DNS server to do phishing, the Website finds out using [its list of] DNS servers on a 'bad' list. The server could also say 'here's how to fix that -- and you can't connect to this site again until you do.' "

But commercializing this technology requires the construction of a DNS blacklist of sorts. "Work has to be done to gather that data," Parisi says.

DNSstuff has been testing the technology for a while now, he says, and the company is actively looking for partners to help it develop it for the market. It doesn't require any changes to existing DNS servers nor to client software, he says. "There wouldn't be a plug-in for the browser... only on the Web server, or something that coordinated with the Web server," he says. "That could be a hardware device that sits in front of the Web server."

Arik Keller, chief operating officer for DNSstuff, says the firm hopes to partner with leading security firms. "We hope to deploy this as an integrated solution with their products, or with other vendors who can help productize and sell it right to the end user focused on e-commerce."

Keller says this DNS reputation model would be akin to email server blacklists. "Our hunch is that this can be as important as IP reputation is to email security."

DNSstuff's technology could be used not only in client machines surfing the Web, but also in cellphones and set-top boxes, according to the company. A bank Web server could detect that a visitor isn't using the standard DNS servers for its ISP, so it would then look up the quality and reputation of the servers and determine whether they were legitimate.

Randy Vaughn, a DNS expert and a professor of information systems at Baylor University, says DNSstuff's new technology sounds intriguing, but there is at least one other method he knows of for detecting DNS settings via a Web server. Still, "if the DNSstuff work is good, it might prove useful for better intelligence about infected hosts for AVers and internal corporate security," Vaughn says.

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