Report DDoS Assault with 25.3 Billion Requests Abused HTTP/2 Multiplexing

Cybersecurity firm Imperva has disclosed that it mitigated a distributed denial-of-service (DDoS) assault with a complete of over 25.3 billion requests on June 27, 2022.

The “robust assault,” which focused an unnamed Chinese language telecommunications firm, is alleged to have lasted for 4 hours and peaked at 3.9 million requests per second (RPS).

“Attackers used HTTP/2 multiplexing, or combining a number of packets into one, to ship a number of requests without delay over particular person connections,” Imperva mentioned in a report printed on September 19.

The assault was launched from a botnet that comprised practically 170,000 totally different IP addresses spanning routers, safety cameras, and compromised servers positioned in additional than 180 international locations, primarily the U.S., Indonesia, and Brazil.


The disclosure additionally comes as net infrastructure supplier Akamai mentioned it fielded a brand new DDoS assault aimed toward a buyer based mostly in Jap Europe on September 12, with assault site visitors spiking at 704.8 million packets per second (pps).

The identical sufferer was beforehand focused on July 21, 2022, similarly through which the assault quantity ramped as much as 853.7 gigabits per second (Gbps) and 659.6 million pps over a interval of 14 hours.

Akamai’s Craig Sparling mentioned the corporate has been “bombarded relentlessly with refined distributed denial-of-service (DDoS) assaults,” indicating that the offensives may very well be politically motivated within the face of Russia’s ongoing warfare towards Ukraine.

Each the disruptive makes an attempt have been UDP flood assaults the place the attacker targets and overwhelms arbitrary ports on the goal host with Person Datagram Protocol (UDP) packets.


UDP, being each connectionless and session-less, makes it a perfect networking protocol for dealing with VoIP site visitors. However these similar traits also can render it extra vulnerable to exploitation.

“With out an preliminary handshake to make sure a authentic connection, UDP channels can be utilized to ship a big quantity of site visitors to any host,” NETSCOUT says.

“There are not any inside protections that may restrict the speed of a UDP flood. Because of this, UDP flood DoS assaults are exceptionally harmful as a result of they are often executed with a restricted quantity of sources.”

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