Important Files In AIX

Files:

/etc/security/environ	lists environment attributes for each user
/etc/security/lastlog	lists last login attributes for each user
/etc/security/limits	lists process resource limits for each user
/etc/security/user	lists extended user attributes for  each user
/usr/lib/security/mkuser.default	lists default attributes for new users
/usr/lib/security/mkuser.sys	script that sets up the user's environment
/etc/passwd	lists basic user attributes for each user
/etc/security/passwd	contains password information for each user
/etc/security/login.cfg	lists login security information for each user
/etc/utmp	contains users that are logged into the system, used by the "who" command
/var/adm/wtmp	contains connect time information for users
/etc/security/failedlogin	contains unsuccessful login attempts
/etc/motd	message of the day that is displayed when the user logs in.
/etc/environment	lists the default environment that new processes will use.
/etc/profile	environment settings for all  users
$HOME/.profile	environment settings for a specific user
/etc/group	lists attributes for each group
/etc/security/group	lists extended attributes for each group

Important /etc/security/user attributes to know about:

account_locked	true or false
expires	Expiration time for a user account.  MMDDHHMMYY,  a value of 0 indicates no expiration
loginretires	Number of invalid login attempts before a users is not allowed to login.  A value of 0 indicates this attribute is disabled.
maxage	Maximum number of weeks a password is valid, a value of 0 indicates unlimited
minage	Minimum number of weeks between password changes.