Phishing Attacks Drive Spike In DNS Threat

The domain name service (DNS) continues to be a favorite tool of cyber criminals: the DNS threat index jumped nearly 60% in the second quarter of this year.

The Infoblox DNS Threat Index is measured by Infoblox and IID, which today published their newest data on malicious activity abusing the Internet's DNS, showing a threat index of 133, up from 122 in the first quarter of 2015, and an average of 100 in 2013 and 2014.

Phishing was up by 74% in Q2, according to the report. "In the second quarter, we saw a lot of phishing domains put up," says Rod Rasmussen, CTO at IID, of the 2Q 2015 activity. "Phishing is old news, but it's successful news" for cybercrime, he says.

No one attack campaign is behind the spike in malicious domains, but popular and pervasive exploit kits such as Angler are a big piece of the puzzle, he says. "The backend stuff is being done by domains," he says.

DNS, which converts domain names into machine-readable IP addresses, has become a popular vehicle for the bad guys to use in the distribution of their malware, the theft of information, and distributed denial-of-service attacks.

The DNS Threat Index has been on the rise for three quarters straight. "This could indicate cybercriminals are expanding the infrastructure to leverage targeted attacks for spreadkign malware and/or exfiltrating data," the Infoblox report said.

Internet pioneer and DNS expert Paul Vixie says there are ways to slow and possibly trip up DNS abuse. He has proposed a "cooling-off period" for DNS providers to activate new domains, an approach that would help minimize domain abuse. A new generation of inexpensive and quick startup domain names has made it easier for bad guys to set up shop in the DNS infrastructure, according to Vixie.

Domain names are as inexpensive as $10 apiece, and can be set up and running in less than 30 seconds, a pace that plays right into the hands of bad guys setting up shop online. Vixie says putting new domains in a temporary hold--for a few minutes or hours--would give the good guys time to vet them, he says.

Meanwhile, DNS is basically "an underappreciated threat vector," notes Arya Barirani, vice president of product marketing at Infoblox.

DNS security also tends to fall through the cracks in organizations. DNS servers often are under the purview of the server operations team, which isn't in charge of security, notes Craig Sanderson, senior director of security products at Infoblox.

"It's really about visibility: there's a significant blind spot in DNS" resources, he says.

It's unclear whether the DNS abuse will continue to climb, but the Hacking Team breach could lead to more malicious domain traffic, IID's Rasmussen says. "We've seen boatloads of infrastructure set up to take advantage of the [dumped] Hacking Team" malware, he says. "We're probably going to see it go up."