DDoS-for-hire services are now actively abusing Datagram Transport Layer Security (D/TLS) servers to amplify Distributed Denial of Service (DDoS) attacks. DDoS booter services, also known as stressers or booters, are now also using DTLS as an amplification vector which puts it in the hands of less sophisticated attackers. More than 4,200 DTLS servers are still reachable over the Internet and ripe for abuse in reflection/amplification DDoS attacks.
Source: https://www.bleepingcomputer.com/news/security/ddos-booters-now-abuse-dtls-servers-to-amplify-attacks/