在缺省情況下,當你登陸到linux系統,它會告訴你該linux發行版的名稱、版本、內核版本、服務器的名稱。對於黑客來說這些信息足夠它入侵你的系統了。你應該只給它顯示一個“login:”提示符。
首先編輯"/etc/rc.d/rc.local" 文件,在下面顯示的這些行前加一個“#”,把輸出信息的命令注釋掉。
# This will overwrite /etc/issue at every boot. So, make any changes you
# want to make to /etc/issue here or you will lose them when you reboot.
#echo "" > /etc/issue
#echo "$R" >> /etc/issue
#echo "Kernel $(uname -r) on $a $(uname -m)" >> /etc/issue
#
#cp -f /etc/issue /etc/issue.net
#echo >> /etc/issue
其次刪除"/etc"目錄下的“isue.net”和"issue"文件:
# rm -f /etc/issue
# rm -f /etc/issue.net