ssh服务的默认端口是22，一般的恶意用户也往往扫描或尝试连接22端口。所以第一步就是修改这个默认端口
打开/etc/ssh/sshd_config，找到
Port 22
然后将22修改为其它没有被占用的端口，如1022。最好在1-1024之间，防止与用户进程端口冲突。
然后重启sshd即可

sudo /etc/init.d/ssh restart

如果说sshd文件不存在

则自己创建一个

#!/bin/sh
# Start/stop/restart the secure shell server:

sshd_start() {
  # Create host keys if needed.
  if [ ! -r /etc/ssh/ssh_host_key ]; then
    /usr/bin/ssh-keygen -t rsa1 -f /etc/ssh/ssh_host_key -N '' 
  fi
  if [ ! -f /etc/ssh/ssh_host_dsa_key ]; then
    /usr/bin/ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key -N ''
  fi
  if [ ! -f /etc/ssh/ssh_host_rsa_key ]; then
    /usr/bin/ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ''
  fi
  /usr/sbin/sshd
}

sshd_stop() {
  killall sshd
}

sshd_restart() {
  if [ -r /var/run/sshd.pid ]; then
    echo "WARNING: killing listener process only.  To kill every sshd process, you must"
    echo "         use 'rc.sshd stop'.  'rc.sshd restart' kills only the parent sshd to"
    echo "         allow an admin logged in through sshd to use 'rc.sshd restart' without"
    echo "         being cut off.  If sshd has been upgraded, new connections will now"
    echo "         use the new version, which should be a safe enough approach."
    kill `cat /var/run/sshd.pid`
  else
    killall sshd
  fi
  sleep 1
  sshd_start
}

case "$1" in
'start')
  sshd_start
  ;;
'stop')
  sshd_stop
  ;;
'restart')
  sshd_restart
  ;;
*)
  echo "usage $0 start|stop|restart"
esac

然后修改文件权限755

再重启就好了