WPyogi,
Thanks for your tips. I’m aware of almost all the suggestions and of course I have backup files before the hack. BTW, it will be useless to restore them if I do not find first how the server was hacked.
Apart from WP 3.7.1, I use on the same server Drupal 6.28 and maybe that is the problem since there is high risk security patch to 6.29.
Any feedback from asefrin and jeanseinomarin will be highly appreciated.
Regards,