Arik Hesseldahl

Recent Posts by Arik Hesseldahl

Denial of Service Attacks Are Getting Bigger and Badder

As we’ve become accustomed to more reliance on the Web in daily life, we’ve also had to become accustomed to the occasional day when someone tries to make a political point by taking a useful website offline.

Often this involves what’s known in security circles as a Distributed Denial Of Service attack, or DDOS. Basically, it involves using an army of hijacked computers to overwhelm a site with so many requests for attention that it’s unable to respond to legitimate requests and thus becomes unavailable.

It has in recent years become a popular method to make a political or ideological point in which the target is some kind of symbol. Earlier this year, there were reports that the method was used by attackers based in Iran against several U.S. banks. Anonymous, the loose affiliation of hackers, has occasionally tried, and occasionally failed, to carry out DDOS attacks. A few years ago, came under an attack by unidentified attackers. And in 2011, a bunch of people were arrested for taking part in some DDOS attacks against PayPal.

Anyway, there’s some new data today from a security company called Prolexic, saying that the amount of bandwidth that DDOS attackers are able to bring to bear on their targets has been increasing at an alarming rate. During the first quarter of the year, the average DDOS attack totaled 48.25 gigabits per second, which is an increase by more than 700 percent versus the prior quarter. The data is contained in a report the company issued today. It’s worth noting that that’s an average, not a peak.

If you liken a DDOS attack to a fire hose, then what this means is that the amount of unwanted water an attacker is able to spray at a target increased sevenfold in one quarter. Anything in excess of 45Gbps is enough to overwhelm even the biggest enterprises and service providers, said Stuart Scholly, Prolexic’s president.

DDOS attackers are getting smarter and are able to command ever bigger armies of compromised computers, and they have studied closely the plumbing of the Internet to better understand its more tender spots.

And it’s not just the amount of bandwidth, but the overall number of packets with which attackers flood a target that’s causing the trouble. The rate of the average DDOS attack in Q1 was more than 32 million packets per second, and anything above 30 million is pretty nasty and difficult to mitigate.

So where do the attacks come from? China was the leading source; DDOS traced to that country accounted for nearly 41 percent of the total, followed by the U.S., which accounted for nearly 22 percent. Germany, Iran and India rounded out the top five. There are more details, including a case study or two about some recent attacks, contained in the report, and if you’re the kind of person who has to fend off the occasional DDOS attack, it may be worth your while to read it. But the main thing to understand is that the attacks themselves are getting nastier.

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I think the NSA has a job to do and we need the NSA. But as (physicist) Robert Oppenheimer said, “When you see something that is technically sweet, you go ahead and do it and argue about what to do about it only after you’ve had your technical success. That is the way it was with the atomic bomb.”

— Phil Zimmerman, PGP inventor and Silent Circle co-founder, in an interview with Om Malik