server always crashed

[Kenzy]

Hello, I want to ask about some things, I always find my server closed for something but I do not know if someone is cracked with DDOS because when it is closed it does not let me or open it in putty because I get that the server error although I have everything well and had to go to the vps panel control and restart it for can enter, and this time he has let me enter putty and I seen this message when I wanted to turn on the server

PLEASE HOW I CAN PROTECT MY SERVER !!
Thanks.

Kodas: Select all

There is a screen on:
        1105.zm (09/21/2021 02:01:27 PM)        (Dead ???)
Remove dead screens with 'screen -wipe'.
There is no screen to be detached matching zm.

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