Short, low-volume DDoS attacks still account for the majority of slam sessions against networks. But large-volume attacks posted a 55% spike in the first quarter over the previous quarter. Corero Network Security released a report on the impact of these attacks on its customers. The report also found that 22% of the attacks lasted 20 minutes or longer. On average, these users encountered 124 attacks per month in first quarter, an increase of 9% over the last quarter, according to the report.”]
Source: https://www.darkreading.com/cloud/majority-of-ddos-attacks-are-short-low-volume-bursts