There were seven times more distributed denial (DDoS) attacks larger than 300 Gbps (gigabit per second) observed during the first six months of 2018 compared to the first half of 2017, NETSCOUT Arbor reveals.

According to the security company’s latest threat intelligence report, the number of large DDoS attacks jumped from 7 to 47 year-over-year in the first half of 2018, and the average DDoS attack size grow 174% during that period. The overall frequency of attacks, however, went down 13%.

The overall assault size was driven by novel techniques and has seen an increase of 37% since memcached appeared (memcached amplification fueled a 1.7 Tbps attack earlier this year). Between March and June 2018, the number of vulnerable (and accessible) memcached servers dropped from 17,000 to 550.