DDoS attacks are growing in size and complexity

Although the total number has fallen slightly, DDoS attacks have become both larger and more complicated in 2021 according to a new report from cloud-based managed security services platform F5 Silverline.

In the last quarter of last year, the average attack size recorded was over 21 Gbps, more than four times the level at the start of 2020. Last year, the record for the largest attack ever recorded was also repeatedly beaten.

An attack in February 2021 measured 500 Gbps. The record was broken again in November with an attack weighing in at 1.4 Tbps, more than five times the previous year’s record.

Volumetric attacks, which use publicly available tools and services to flood a target’s network with more bandwidth than they can handle, remained the most common form of DDoS in 2021, accounting for 59% of all recorded attacks, down slightly from 66%. in the previous year.

27% of attacks in 2021 leveraged TCP, up from 17% the previous year, showing the requirements for more complex application and protocol-based attacks. In terms of specific attack methods, there have also been notable changes, with DNS query attacks becoming more common, up 3.5% year over year.

“Along with changes in attack type, we continued to see a high prevalence of multi-vector attacks, including the 1.4 Tbps incident that used a combination of DNS reflection and HTTPS GETS,” said David Warburton, Director from F5 Labs. “This was especially true earlier in the year, when multi-vector attacks significantly outnumbered single-vector attacks. This illustrates the increasingly challenging threat protection landscape as defenders need to use more parallel techniques to mitigate these more sophisticated attacks and prevent a denial of service.”

Banking, financial services and insurance (BFSI) is the industry most targeted by DDoS attacks in 2021, accounting for more than a quarter of the total volume. This continues a trend that has seen attacks on BSFI increase steadily since the start of 2020.

However, technology – the most targeted sector in 2020 – has dropped to fourth place behind telecommunications and education. Between them, these four sectors account for 75% of all recorded attacks, with a long tail of others, including energy, retail, healthcare, transport and legal, which have seen virtually no activity. undesirable.

“As the sophistication and variety of DDoS attacks increase, organizations will find themselves using a wide variety of measures to protect against them, including preflight controls to inspect and limit traffic reaching endpoints, and vendors managed services that can work alongside internal security teams to both prevent attacks and act quickly to mitigate those in progress,” adds Warburton.

The full report is available on the F5 Silverline website.

Photo credit: DD Images/Shutterstock

Sharon D. Cole