We have a few samples of the SQL injection attempts here: http://blog.sucuri.net/2014/10/drupal-sql-injection-attempts-in-the-wild.html http://blog.sucuri.net/

We have a few samples of the SQL injection attempts here: http://blog.sucuri.net/2014/10/drupal-sql-injection-attempts-in-the-wild.html http://blog.sucuri.net/2014/10/drupal-sql-injection-attempts... In there you can see the type of backdoors being added (generally fake users with admin-level privileges).