Website repeatedly hacked

I have been having major issues with the latest WordPress 4.5.3 hacked repeatedly recently. Each time I have deleted everything from the FTP, except the folder wp-content and then reupload all the deleted files from the fresh WordPress zip. I have also changed admin password, MySQL password and salts in WP-config every time after the attack.

All the plugins are updated, so I really don’t know where the problem could lye. I have thus downloaded all the infected files from the last attack, you may download them from this link if it helps any way in diagnosis: [removed, please don’t post malware here]

I was wondering what else could I do?