Old contact form being spammed

Hi,
I am getting 3-5 spam submissions a day from a contact us 1 form from my website. I use gravity forms on my site and can’t find this particular form in either my gravity form list or as shorcode on a page. Searching for the name Henrynaf Henrynaf in any of our form enteries shows no entries. I have checked All, Active, Inactive and trash in gravity forms. What can I do to blck this spam?

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