Some guy gave himself op with using /op command and we have pureperms plugin so they should not be able to use this command. Maybe he used an illegal client to send illegal packets. Is there anyone has idea? In console it says [Playername: playername opped playername]
It just means that he somehow had the permissions for the /op command. There are no illegal packets or such.
we already did that but its not the issue, issue is pocketmine has this bug in all pocketmine servers
Can you reproduce this bug in clean installation? Check this: https://forums.pmmp.io/threads/how-do-servers-get-hacked.5928/#post-52393