Not one month after Incapsula announced its new DNS and infrastructure protection services, our new ’Behemoth‘ scrubbers were put to the test — mitigating a massive, multi-vector DDoS attack, peaking at 110+ Gbps and 90+ million packets per second.

Like the proud parents we are, we couldn’t help but brag about Behemoth’s success on Facebook and Twitter. One of these tweets caught the attention of Mohit Kumar, founder and editor-in-chief of The Hacker News (THN), who shot us an email with some questions. In responding we told him it appeared the attack “wasn’t going to stop any time soon”.

In retrospect, this turned to be a serious understatement.

Days after the story appeared in THN magazine the attack continued to rumble on. Its presence became a regular fixture of our daily routine, to the point where we started second-guessing traffic reports which didn’t include a few tens of millions of filtered-out DDoS packets.

38 Day Long DDoS Attack - Zabbix Screen

DDoS traffic generated by DNS and SYN floods over the course of the attack.

During this time we saw the offenders throwing everything they had at us, but the kitchen sink. They tried everything from massive network layer DDoS attacks to focused application layer (HTTP) floods, followed by dozens of SQLI and XSS attempts — all foiled by the Incapsula web application firewall.

Typically, the perpetrators were simultaneously using at least two of these attack vectors. It was not uncommon to see them turning up the heat with “all guns blazing” five-vector attacks.

At all times, they continued to use extremely large DNS floods, usually comprising several tens of millions requests per second. Often these were accompanied by large SYN floods, also aimed at Incapsula’s DNS infrastructure.

It should be noted that, in the last few month, we have mitigated many more of these massive DNS floods, which are quickly becoming the new weapon of choice for DDoS offenders.

38 Days and 50 Petabits of DDoS

The DDoS attack lasted 38 days, during which Incapsula’s scrubbing servers filtered out 50+ petabits (51,000+ terabits) of malicious traffic.

Interestingly, while the offenders did switch between several targets, they consistently targeted the websites of one Incapsula client — a video game company that onboarded Incapsula services on the eve of the attack.

Clearly, this organization was the real target. Combined with the extreme determination of the attackers, one can assume that the DDoS attack was the result of a business feud. The goal was nothing short of a complete takedown of this online business.

Behemoth Scrubber in Action

A Glimpse Into Incapsula’s Mitigation Process | View Hi-Res Image

Pareto’s Law – 80% of DDoS Traffic From 20% IPs

The ‘business feud’ theory is reinforced by the resources used during the attack. Looking at source IP data, Incapsula noticed the majority of malicious packets were originating from the same IP ranges. We knew that 20% of C-classes are typically responsible for ~80% of all DDoS traffic.

In other words, we detected offenders who had continuous access to several very powerful network resources. These were strong and reliable enough to sustain a month-long offensive — while also generating 90+ Gbps of unamplified DDoS traffic.

This is a long way off from what you would expect from an off-the-shelf botnet for hire. The perpetrators weren’t script kiddies looking to make a quick buck with a 20 Gbps DDoS attack and a $300 ransom note.

Whoever they were, they were DDoSing for a living.

Just In Time for Graduation

As previously mentioned, the attack started shortly after Incapsula rolled out our new ‘Behemoth’ scrubbing servers. While these new mega-scrubbers were deployed after a month of internal tests, this DDoS event was their true “rite of passage”.

During the weeks of the attack, an observer only had to look at the satisfied smiles of Incapsula’s team to see that we couldn’t have asked for a better graduation moment.

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