This is very common on my FTP server. I do not have an account by the name of "Administrator", and my password is very secure, so when I saw it I didn't really care about it.
Funny, upon checking my FTP server look what I see:
Code:
(000003) 27/12/2007 15:37:47 PM - (not logged in) (211.239.186.14)> USER Administrator
(000003) 27/12/2007 15:37:47 PM - (not logged in) (211.239.186.14)> 331 Password required for administrator
(000003) 27/12/2007 15:37:49 PM - (not logged in) (211.239.186.14)> PASS ******
(000003) 27/12/2007 15:37:49 PM - (not logged in) (211.239.186.14)> 421 Temporarily banned for too many failed login attempts
As you see, it's very common and not really something you should worry about. My server has the set limit of login attempts, and as you can see, it banned the IP for that.