本脚本是第二次更新，已经大量应用在某大型媒体网站体系中，加入了之前没有想到的一些安全设置。使用方法将其复制，保存为一个shell文件，比如security.sh.将其上传到Linux服务器上，执行sh security.sh，就可以使用该脚本了！
建议根据自己的实际需要来修改此脚本，不要盲目使用！

#!/bin/bash
# desc: setup linux system security
# author:coralzd
# powered by www.freebsdsystem.org
# version 0.1.2 written by 2011.05.03
#account setup

passwd -l xfs
passwd -l news
passwd -l nscd
passwd -l dbus
passwd -l vcsa
passwd -l games
passwd -l nobody
passwd -l avahi
passwd -l haldaemon
passwd -l gopher
passwd -l ftp
passwd -l mailnull
passwd -l pcap
passwd -l mail
passwd -l shutdown
passwd -l halt
passwd -l uucp
passwd -l operator
passwd -l sync
passwd -l adm
passwd -l lp

# chattr /etc/passwd /etc/shadow
chattr +i /etc/passwd
chattr +i /etc/shadow
chattr +i /etc/group
chattr +i /etc/gshadow

# add continue input failure 3 ,passwd unlock time 5 minite
sed -i 's#auth required pam_env.so#auth required pam_env.so\nauth required pam_tally.so onerr=fail deny=3 unlock_time=300\nauth required /lib/security/$ISA/pam_tally.so onerr=fail deny=3 unlock_time=300#' /etc/pam.d/system-auth
# system timeout 5 minite auto logout
echo "TMOUT=300" >>/etc/profile

# will system save history command list to 10
sed -i "s/HISTSIZE=1000/HISTSIZE=10/" /etc/profile

# enable /etc/profile go!
source /etc/profile

# add syncookie enable /etc/sysctl.conf
echo "net.ipv4.tcp_syncookies=1" >> /etc/sysctl.conf

sysctl -p # exec sysctl.conf enable
# optimizer sshd_config

sed -i "s/#MaxAuthTries 6/MaxAuthTries 6/" /etc/ssh/sshd_config
sed -i "s/#UseDNS yes/UseDNS no/" /etc/ssh/sshd_config

# limit chmod important commands
chmod 700 /bin/ping
chmod 700 /usr/bin/finger
chmod 700 /usr/bin/who
chmod 700 /usr/bin/w
chmod 700 /usr/bin/locate
chmod 700 /usr/bin/whereis
chmod 700 /sbin/ifconfig
chmod 700 /usr/bin/pico
chmod 700 /bin/vi
chmod 700 /usr/bin/which
chmod 700 /usr/bin/gcc
chmod 700 /usr/bin/make
chmod 700 /bin/rpm

# history security

chattr +a /root/.bash_history
chattr +i /root/.bash_history

# write important command md5
cat > list << "EOF" &&
/bin/ping
/bin/finger
/usr/bin/who
/usr/bin/w
/usr/bin/locate
/usr/bin/whereis
/sbin/ifconfig
/bin/pico
/bin/vi
/usr/bin/vim
/usr/bin/which
/usr/bin/gcc
/usr/bin/make
/bin/rpm
EOF

for i in `cat list`
do
if [ ! -x $i ];then
echo "$i not found,no md5sum!"
else
md5sum $i >> /var/log/`hostname`.log
fi
done
rm -f list