1.5.1 (101) Maybe hack on servers pw1.5.1

My question is as follows:

I have a server pw1.5.1. Recently I discovered that some members were able to hack into my pwadmin and perform duper.
Besides, I also discovered they can make server disconnected.

and I have yet to find the cause and a solution.
So there could actually hack on servers pw1.5.1

and how to hack and how to prevent it happens.
thank you.

buy pwadmin by alexdnepro, and delete pwadmin by ronny

????

why so

Duplicate items to 1.5.1 is not easy. Change passwords for ftp and pwadmin

Сделай ограничение на порт pwAdmin, чтобы было соединение только с твоего IP.
Редактируй файл rc.local
iptables -A INPUT -p tcp -s твой IP -j ACCEPT
iptables -A INPUT -p tcp --dport номер порта pwAdmin -j DROP