September 24, 2017

Security Lessons from the Big DDoS Attacks

Last week saw news of new Distributed Denial of Service (DDoS) attacks. These may be the largest DDoS attacks ever, peaking at about 300 Gbps (that is, 300 billion bits per second) of traffic aimed at the target but, notwithstanding some of the breathless news coverage, these attacks are not vastly larger than anything before. The attacks are news, but not big news.

The attacks were aimed at Spamhaus, which publishes lists of purported spammers. Unsurprisingly, the attackers appear to be associated with spamming—specifically, with Cyberbunker, which is accused of hosting spammers.

One interesting aspect of the attacks is the way they exploited externalities. “Externality” is an economics term. For our purposes, it describes a situation where a party could efficiently prevent harm to others—that is, a dollar’s worth of harm could be prevented by spending less than a dollar on prevention—but the harm is not prevented because the party has little or no incentive to prevent harm to strangers. Externalities are a common problem in security—they’re one of the reasons the market has trouble providing adequate security. The recent DDoS attacks exploited three separate externalities.
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