root@localhotst# find / -type f -perm +6000 -ls 59520 30 -rwsr-xr-x 1 root root 30560 Apr 15 1999 /usr/bin/chage 59560 16 -r-sr-sr-x 1 root lp 15816 Jan 6 2000 /usr/bin/lpq  

root@localhotst# chmod -s /usr/bin/chage /usr/bin/lpq root@localhotst# ls -l /usr/bin/lpq /usr/bin/chage -rwxr-xr-x 1 root root 30560 Apr 15 1999 /usr/bin/chage -r-xr-xr-x 1 root lp 15816 Jan 6 2000 /usr/bin/lpq  

root@localhost# find / -perm -2 ! -type l -ls  

root@localhost# find / -nouser -o -nogroup  

root@localhost# chattr +i /bin/login root@localhost# chattr +a /var/log/messages root@localhost# lsattr /bin/login /var/log/messages ----i--- /bin/login -----a-- /var/log/messages  

root@localhost#chkconfig --list root@localhost#chkconfig --del  

/bin/netstat -a -p --inet  

root@localhost# rpm -e root@localhost# dpkg -r  

root@localhost# rpm -qvl root@localhost# dpkg -c  

root@localhost# rpm -qvia root@localhost# dpkg -l  

root@localhost# rpm -qvpl root@localhost# dpkg -c  

root@localhost# rpm -qpi root@localhost# dpkg -I  

root@localhost# rpm -Va root@localhost# debsums -a  

root@localhost# rpm -Uvh root@localhost# dpkg -i  

root@localhost# md5sum package-name 995d4f40cda13eacd2beaf35c1c4d5c2 package-name  

root@localhost# md5sum /usr/bin/netstat 995d4f40cda13eacd2beaf35c1c7d8c1 /usr/bin/netstat  

oot@localhost#: /usr/TSS/bin/twadmin -m P policy.txt Khởi tạo cơ sở dữ liệu theo File nội quy chính: root@localhost#: /usr/TSS/bin/tripwire -init Hiển thị cơ sở dữ liệu: root@localhost#: /usr/TSS/bin/twprint -m d Tạo thông báo kết quả theo ngày: root@localhost#: /usr/TSS/bin/tripwire -m c -t 1 -M Cập nhật cơ sở dữ liệu theo File nội quy và báo cáo hàng ngày: root@localhost#: /usr/TSS/bin/tripwire --update --polfile policy/tw.pol \ --twrfile report/-.twr  

host2$ ssh-keygen Generating RSA keys: ...ooooooO....ooooooO Key generation complete. Enter file in which to save the key (/home/binhnx2000/.ssh/identity): Created directory '/home/binhnx2000/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/binhnx2000/.ssh/identity. Your public key has been saved in /home/binhnx2000/.ssh/identity.pub. The key fingerprint is: ac:42:11:c8:0d:b6:7e:b4:06:6a:a3:a7:e8:2c:b0:12 binhnx2000@host2  

host2$ mkdir -m 700 ~dave/.ssh host2$ cp /mnt/floppy/identity.pub ~binhnx2000/.ssh/authorized_keys  

root@localhost$ ssh host2 Enter passphrase for RSA key 'binhnx2000@localhost': Last login: Sat Aug 15 17:13:01 2000 from localhost No mail. host2$  

root@localhost$ scp /tmp/file.tar.gz host2:/home/binhnx2000 Enter passphrase for RSA key 'binhnx2000@localhost: file.tar.gz 100% |***************************| 98304 00:00  

ALL:ALL  

ALL: ALL: /bin/mail \ -s “%s connection attempt from %c” admin@mydom.com  

sshd: magneto.mydom.com, juggernaut.mydom.com in.ftpd: 192.168.1.  

root@localhost# echo “0” > /proc/sys/net/ipv4/ip_forward  

Listen 127.0.0.1:80  

Options None AllowOverride None Order deny,allow Deny from all  

# Deny all accesses by default Order deny,allow # Allow access to local machine Allow from 127.0.0.1 # Allow access to entire local network Allow from 192.168.1. # Allow access to single remote host Allow from 192.168.5.3 # Deny from everyone else Deny from all  

Order Deny,Allow Deny from All Allow from 192.168.1.11 AuthName “Private Information” AuthType Basic AuthUserFile /etc/httpd/conf/private-users AuthGroupFile /etc/httpd/conf/private-groups require group  

root@localhost# htpasswd -cm /etc/httpd/conf/private-users binhnx2000 New password: Re-type new password: Adding password for user binhnx2000  

root@localhost# chmod 700 /etc/httpd/conf/private-users root@localhost# chown root /etc/httpd/conf/private-users  

// Allow transfer only to our slave name server. Allow queries // only by hosts in the 192.168.1.0 network. zone “mydomain.com” { type master; file “master/db.mydomain.com”; allow-transfer { 192.168.1.6; }; allow-query { 192.168.1.0/24; }; };  

// Disable the ability to determine the version of BIND running zone “bind” chaos { type master; file “master/bind”; allow-query { localhost; }; };  

$TTL 1d @ CHAOS SOA localhost. root.localhost. ( 1 ; serial 3H ; refresh 15M ; retry 1W ; expire 1D ) ; minimum NS localhost.  

root@localhost# useradd -M -r -d /var/named -s /bin/false named root@localhost# groupadd -r named  

# Monitor authentication attempts auth.*;authpriv.* /var/log/authlog # Monitor all kernel messages kern.* /var/log/kernlog # Monitor all warning and error messages *.warn;*.err /var/log/syslog # Send a copy to remote loghost. Configure syslogd init # script to run with -r -s domain.com options on log # server. Ensure a high level of security on the log # server! *.info @loghost auth.*;authpriv.* @loghost  

root@localhost# chmod 751 /var/log /etc/logrotate.d root@localhost## chmod 640 /etc/syslog.conf /etc/logrotate.conf root@localhost## chmod 640 /var/log/*log  

/sbin/lilo: image = /boot/vmlinuz-2.2.17 label = Linux read-only restricted password = your-password  

0-59/30 * * * * root /usr/sbin/ntpdate -su time.timehost.com