Hi, my index.php file was hacked today, leaving just the hackers signature. I have checked all my directories and files and all are attributes are set properly. I'm using 2.0.5, the Almost Spring theme and the following plugins:
Breadcrumb Navigation XT
Collapsing Category Menus
del.icio.us - Bookmark this!
Any help in finding this backdoor would be very useful. My hosting company says it's to do with the php software (ie WP), but they would say that! ;) All passwords are unique, changed regularly and I have no spyware/keyloggers etc on my machines.