Linux System Security Check Method

Check the system password file in Linux and check the file modification date.

[Root @ Fedora ~] # Ls-l/etc/passwd

View privileged users in the passwd file

[Root @ fedora ~] # Awk-F: '$3 = 0 {print $1}'/etc/passwd

Check whether there is a blank password account in the system.

Awk-F: 'length ($2) = 0 {print $1} '/etc/shadow

Check the system daemon process

Cat/etc/inetd. conf | grep-v "^ #"

Check network connection and listening port

Netstat-

Netstat-rn

Ifconfig-

View historical records of all users logging on to the local machine under normal conditions

Last

Check the core file in the system

Find/-name core-exec ls-l {}\;

Check System File integrity

Rpm-qf/bin/ls

Rpm-qf/bin/login

Md5sum-B file name

Md5sum-t file name

Check for backdoor

Cat/etc/crontab

Ls/var/spool/cron/

Cat/etc/rc. d/rc. local

Ls/etc/rc. d

Ls/etc/rc3.d

Find/-type f-perm 4000