A newly discovered network botnet comprising an estimated 30,000 webcams and video recorders—with the largest concentration in the US—has been delivering what is likely to be the biggest denial-of-service attack ever seen, a security researcher inside Nokia said.

The botnet, tracked under the name Eleven11bot, first came to light in late February when researchers inside Nokia’s Deepfield Emergency Response Team observed large numbers of geographically dispersed IP addresses delivering “hyper-volumetric attacks.” Eleven11bot has been delivering large-scale attacks ever since.

Volumetric DDoSes shut down services by consuming all available bandwidth either inside the targeted network or its connection to the Internet. This approach works differently than exhaustion DDoSes, which over-exert the computing resources of a server. Hypervolumetric attacks are volumetric DDoses that deliver staggering amounts of data, typically measured in the terabits per second. Johnny-come-lately botnet sets a new record

At 30,000 devices, the Eleven11bot was already exceptionally large (although some botnets exceed well over 100,000 devices). Most of the IP addresses participating, Nokia researcher Jérôme Meyer told me, had never been seen engaging in DDoS attacks.

Besides a 30,000-node botnet seeming to appear overnight, another salient feature of Eleven11bot is the record-size volume of data it sends its targets. The largest one Nokia has seen from Eleven11bot so far occurred on February 27 and peaked at about 6.5 terabits per second. The previous record for a volumetric attack was reported in January at 5.6 Tbps.

“Eleven11bot has targeted diverse sectors, including communications service providers and gaming hosting infrastructure, leveraging a variety of attack vectors,” Meyer wrote. While in some cases the attacks are based on the volume of data, others focus on flooding a connection with more data packets than a connection can handle, with numbers ranging from a “few hundred thousand to several hundred million packets per second.” Service degradation caused in some attacks has lasted multiple days, with some remaining ongoing as of the time this post went live.