Bungeecord proxy is bot and everything is lagging?

I run a server network in Minecraft. Only since yesterday have any players been running the Bungeecord Proxy with bots, it comes to lags and the pings of the players shoot up. Unfortunately I have not found a way to fix this. I enclose a screenshot from the console.

Feel free to write if you have more questions.

Try to block / ban the players and install a plugin against DDos attacks