Information
Monitor session initiation events. The parameters in this section track changes to the files associated with session events.
- /var/run/utmp - tracks all currently logged in users.
- /var/log/wtmp - file tracks logins, logouts, shutdown, and reboot events.
- /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 "session."
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).
Solution
Note:
- The -w option is deprecated and the rule should be updated in accordance with the Remediation Procedure.
- For best performance, the arch field should be supplied in the rule. The individual permissions will cause the selection of specific system calls that use that kind of access. Not supplying the arch will cause the selection of all system calls which will affect performance as all system calls will be evaluated.
- Edit or create a file in the /etc/audit/rules.d/ directory, ending inrules extension, with the relevant rules to monitor session initiation information.
Example:
# printf "
-a always,exit -F arch=b64 -S all -F path=/var/run/utmp -F perm=wa -F key=session
-a always,exit -F arch=b64 -S all -F path=/var/log/wtmp -F perm=wa -F key=session
-a always,exit -F arch=b64 -S all -F path=/var/log/btmp -F perm=wa -F key=session
" >> /etc/audit/rules.d/50-session.rules <xhtml:ol start="2"> - Merge and load the rules into active configuration:
# augenrules --load <xhtml:ol start="3"> - Check if reboot is required:
# if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi