Information
Record changes to network environment files or system calls. The files being monitored are:
- /etc/issue and /etc/issue.net - messages displayed pre-login
Monitoring /etc/issue and /etc/issue.net is important, as intruders could put disinformation into those files and trick users into providing information to the intruder.
Solution
- Edit or create a file in the /etc/audit/rules.d/ directory, ending in .rules extension, with the relevant rules to monitor events that modify the system's network environment.
Example:
# printf "
-w /etc/issue -p wa -k system-locale
-w /etc/issue.net -p wa -k system-locale
" >> /etc/audit/rules.d/50-etc_issue_system_locale.rules
- Merge and load the rules into active configuration:
# augenrules --load
- Check if reboot is required:
# if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi