Important!!! - Your forum is spammed, please read!
We just detected your forum is spammed and you got many PDF spam files uploaded in /wp-content/uploads/wpforo/default_attachemnts/ folder. You're using an old version of wpForo forum plugin. Please update it to wpForo 1.2.0 it comes with Anti-spam functions and it'll let you delete all spam files. More info you can find in wpForo changelog: