There is a form in account which was not created by me

On june 8 a form named "workshop_checkliste_form1" was added by "I don't know who". The form has nothing to do with one of my projects. Probably it was made for a company with the name "Northridge". What happened here? Why was this PDF added to my account?

Our apologies. It looks like a glitch in the import tool. You've requested two PDFs and I think the tool mistakenly imported this form in your account. This is not a kind of a problem where someone had the access to your account so nothing to worry about. You can just delete the form. I will also inquire about this to our developers. If this happens again, let us know right away so we can investigate further.