Failed to open Steam: permission denied

Hey guys I have a problem with my website since I had to delete some malware on my website.

After I deleted the malware I now gave plugin.php all the rights it needs 755 so I don’t know what else I can do. My host provider told me to delete all the old plugins I wasn’t using anymore and it might help but sadly it didn’t either.
Do you guys have any tipps for me?

Warning: file_get_contents(/homepages/46/d72876648/htdocs/Morningelegance/wp-admin/bvgwtivd.php): failed to open stream: Permission denied in?/homepages/46/d72876648/htdocs/Morningelegance/wp-includes/plugin.php(513) : runtime-created function?on line?1

The page I need help with: [log in to see the link]