It's famous as "NTP Amplification Attack" 😁
Discussion
Googling now:

Why do hackers have to f**k up perfectly good protocols:
https://www.akamai.com/glossary/what-is-an-ntp-amplification-attack
nostr:note105fcp9k2fwjxgmw2z3sy0qgjs8h2m6wheue48fkfv7yygm663zfsu4qy36