From late 2018 Memcached amplification method attacks have emerged.

Malicious actors have started abusing the Memcached protocol to launch distributed DDoS / DrDos) attacks.

Memcached is a free and open source distributed memory caching system designed to work with a large number of open connections. Clients can communicate with Memcached servers via TCP or UDP on port 11211 (Memcached Abused for DDoS Amplification Attacks – 02 2018)