Hi!
This is an leak of plugin AAC (Advanced Anti Cheat)
I'm not tested this, and It's possibly don't working
Official spigot page:
spigotleaks.phpnet.us/plugin/AAC-1.9.2.jar
[url=https://www.spigotmc.org/resources/aac-advanced-anti-cheat-hack-kill-aura-blocker.6442/][/url]