List failed login attempts on Mavericks
You can use this Terminal command:

cat /private/var/log/system.log | grep "Failed to authenticate"




Feb 11 16:48:04 g authorizationhost[15313]: Failed to authenticate user &lt;grgarside&gt; (error: 9).
Feb 11 16:48:06 g authorizationhost[15313]: Failed to authenticate user &lt;grgarside&gt; (error: 9).