Email members with unique attachment

I am hoping for tips, suggestions, or general pointing in the right direction for this feature, assuming it’s possible.

Using the Communicate option is preferred but not required. What we would like to do is send a semi-generic email to members of a specific group/role. But, each recipient would have a PDF attached that is unique to them by way of their member ID.

Is this doable with existing add-ons or would it likely be a custom built add-on?