4.1.9 Ensure session initiation information is collected (Scored)

Level 2 - Server
Level 2 - Workstation 

Monitor session initiation events. The parameters in this section track changes to the files associated with session events. The file /var/run/utmp file tracks all currently logged in users. The /var/log/wtmp file tracks logins, logouts, shutdown, and reboot events. All audit records will be tagged with the identifier “session.” The file /var/log/btmp keeps track of failed login attempts and can be read by entering the command /usr/bin/last -f /var/log/btmp. All audit records will be tagged with the identifier “logins.”

Monitoring these files for changes could alert a system administrator to logins occurring at unusual hours, which could indicate intruder activity (i.e. a user logging in at a time when they do not normally log in).

Run the following command and verify output matches:

# grep session /etc/audit/audit.rules 
-w /var/run/utmp -p wa -k session 
-w /var/log/wtmp -p wa -k session 
-w /var/log/btmp -p wa -k session

Add the following lines to the /etc/audit/audit.rules file:

-w /var/run/utmp -p wa -k session 
-w /var/log/wtmp -p wa -k session 
-w /var/log/btmp -p wa -k session

The last command can be used to read /var/log/wtmp (last with no parameters) and /var/run/utmp (last -f /var/run/utmp)