Command: ls -l /etc/passwd*

-rw-r--r-- 1 root root 1335 2007-05-27 20:55 /etc/passwd
-rw------- 1 root root 1306 2007-05-27 20:55 /etc/passwd-
-rw------- 1 root root 1231 2006-06-20 13:29 /etc/passwd.bak