hacked by ksg-crew : CYSC.DEF.KSG.CREW.EXPLIZIT

I have changed all my passwords, but I am concerned how they got in in the first place.
Any ideas?




TO WHOM IT MAY CONCERN:

The security experts of cyscon GmbH like to ask you to remove/review the below mentioned file from/on your servers. At least one of our scanners detect it, and we consider it as malicious:

################################################## ######################
# begin logs

IP: 216.246.77.77
URL: http://www.goodguyssecurity.com/wp-c...a367/index.php
Port: 80
Tested on: Fri, 27 Jul 2012 03:13:50 0200
Result: CYSC.DEF.KSG.CREW.EXPLIZIT

# end logs