[PowerPC603]

Did they enter using Rcon?
Change your rcon password and restart server.

They could have simply found your rcon password and they're probably using the exit command to shutdown your server.

You could try to print whatever command is entered under OnRconCommand.
Then you can see if this is the cause.

Also print something under OnRconLoginAttempt.
Print the IP, so you know which IP to ban if they successfully login through rcon.

pawn Код:

public OnRconCommand(cmd[])
{
    printf("[RCON]: Command '%s' was used", cmd);

    return 0;
}

public OnRconLoginAttempt(ip[], password[], success)
{
    printf("[RCON login attempt]: IP '%s' tried to login to the server with password '%s'", ip, password);
    if (success)
        printf("[RCON login attempt]: Logging in was sucessful");
    else
        printf("[RCON login attempt]: Logging in failed");

    return 1;
}

This could help if they used rcon to shutdown your server.