I use MigraDoc for creating pdf documents in the project.

Code below shows how I work with library:

    var document = new Document { Info = { Author = "title" } }; 
        Section section = document.AddSection(); 
        Paragraph paragraph = section.AddParagraph("Title"); 
        var renderer = new PdfDocumentRenderer(true, PdfSharp.Pdf.PdfFontEmbedding.Always) { Document = document }; 
        renderer.RenderDocument();

So, I'm looking for a way to adding link to web resource inside pdf.