Information
Record events affecting the group , passwd (user IDs), shadow and gshadow (passwords) or /etc/security/opasswd (old passwords, based on remember parameter in the PAM configuration) files. The parameters in this section will watch the files to see if they have been opened for write or have had attribute changes (e.g. permissions) and tag them with the identifier 'identity' in the audit log file.
Rationale:
Unexpected changes to these files could be an indication that the system has been compromised and that an unauthorized user is attempting to hide their activities or compromise additional accounts.
Solution
Add the following lines to the /etc/audit/audit.rules file:
-w /etc/group -p wa -k identity
-w /etc/passwd -p wa -k identity
-w /etc/gshadow -p wa -k identity
-w /etc/shadow -p wa -k identity
-w /etc/security/opasswd -p wa -k identity
Impact:
Auditing can produce a large amount of information, creating large and/or many audit log files.
Notes:
Reloading the auditd config to set active settings may require a system reboot.