If you still think distributed denial-of-service (DDoS) attacks are merely old-school, outdated, pain in the neck disruption campaigns waged by hacktivists or script kiddies, think again: about half of all enterprises were hit with a DDoS attack last year and most ISPs and enterprises also suffered more stealthy DDoS attacks aimed at flying under the radar.
Some 90% of ISP and enterprise respondents in Arbor Networks' 10th Annual Worldwide Infrastructure Security Report say they experienced application-layer (versus network connection-sapping) DDoS attacks, and 42% say they were hit by DDoS attacks that used a combination of bandwidth-sapping, application-layer, and state exhaustion methods. HTTP- and DNS are the top two targets of application-layer attacks, according to the report, which was released today.
But so-called volumetric attacks, which bombard a targeted organization or ISP's network connections, still outnumber application-layer attacks, accounting for about two-thirds of all DDoS attacks in the past year. DDoS attacks are also becoming more frequent: 38% say they had been hit by more than 21 DDoS attacks per month in 2014, twice the number of organizations as in 2013.
The biggest DDoS attack in 2014 came in at a whopping 400 gigabits-per-second, according to Arbor. That's a far cry from the record-breaking 8Gbps when Arbor did its first report 10 years ago.
It's not all that's changed in DDoS attacks. "Application layer attacks weren't even a topic of discussion 10 years ago. That's a huge shift," says Gary Sockrider, solutions architect at Arbor Networks.
Application-layer attacks aim to overwhelm a server's resources, rather than the Internet pipe, and they operate "low and slow" to go undetected until it's too late. "If you have an application running on a server behind a 10Gig Internet connection, you could have something using only 1% of that pipe, and a 10 meg attack could exhaust the server resources," Sockrider says.
These attacks are often successful because many DDoS detection technologies can't see upper-layer application-layer traffic anomalies, and if they do, it may not be enough to trigger an alarm, he says. "They tend to be combined with volumetric attacks, which set off an alarm. While you are reacting to that, the application layer attack is sneaking through," so it can be used as a distraction for the real attack, he says.
According to Arbor's report, hacktivism isn't the number one motive for a DDoS anymore: 37% of these types of attacks are disputes between crime gangs; 36% stem from competitive rivalry between businesses or gamers; 34% from flash crowds or hacktivism; 28% for hiding data exfiltration or other compromises; 25% for financial market manipulation; and 24% for extortion purposes.
But not all anti-DDoS vendors are seeing a jump in app-layer DDoS attacks. David Fernandez, head of the Akamai PLXsert team, says while Akamai sees DDoS attacks overall on the rise, there has been a decline in application-layer DDoS attacks. In the fourth quarter of 2014, Akamai saw application-layer attacks accounting for about 10% of all DDoS attacks, and infrastructure/volumetric attacks making up nearly 90% of them.
"The dramatic increase in overall DDoS attacks mitigated in Q4 2014 is an example of how attackers considered this attack type a primary vector in their arsenal," Fernandez says. "New attack types and increased sophistication are always becoming more apparent."
Meanwhile, Arbor's data syncs with DDoS trends Incapsula is seeing, says Igal Zeifman product evangelist at Incapsula. His firm's research shows 45% of all businesses have been hit with a DDoS attack at least once in the past year. "Any time you see a large number like 90 percent, it sounds high, but being hit by a cyberattack has become a part of doing business online," Zeifman says.
Not surprisingly, cloud services are being targeted as well. More than 25% of ISPs and enterprises surveyed by Arbor report seeing cloud services being targeted by DDoS campaigns. And more than one-third of data center operators say they were hit by a DDoS that sapped their Internet bandwidth, and 44% of data centers experienced revenue loss from a DDoS attack.
Arbor's report draws some 287 respondent organizations, including ISPs, hosting and mobie providers, as well as enterprises worldwide. Around 60% were service providers, and 30% enterprises, education, and government organizations.