Distributed Denial of Service (DDoS) attacks are happening ever more often and growing ever bigger. At 2.4 terabits per second (Tbps), the DDoS attack Microsoft just successfully defended European Azure cloud users against could be the biggest one to date.
What we know for certain is it's the biggest DDoS attack on an Azure cloud customer. It was bigger than the previous high, 2020's Azure 1 Tbps attack, and Microsoft reported it was "higher than any network volumetric event previously detected on Azure."
[...] Microsoft isn't saying which was used in this case but it did mention DNS. Attacks exploiting DNS can produce 28 to 54 times the original number of bytes. So, if an attacker sends a request payload of 64 bytes to a DNS server, they can generate over 3,400 bytes of unwanted traffic to an attack target.
While Microsoft also didn't go into detail about how it blocked the attack, the company said Azure's DDoS protection platform, built on distributed DDoS detection and mitigation pipelines, can absorb tens of terabits of DDoS attacks: "This aggregated, distributed mitigation capacity can massively scale to absorb the highest volume of DDoS threats, providing our customers the protection they need."