If you open the PDF in notepad++ you'll find:
9 0 obj <</Filter/FlateDecode/Length 79100/Length1 171804>> stream xœì} XTGºvÕ9½/t7Ðl ..... many more bytes ... ëH| endstream endobj 10 0 obj
and that object is referenced here at the end in the /FontFile2 instruction:
6 0 obj <</Type/FontDescriptor/FontName/ABCDEE+Calibri/Flags 32/ItalicAngle 0/Ascent 750/Descent -250/CapHeight 750/AvgWidth 521/MaxWidth 1743/FontWeight 400/XHeight 250/StemV 52/FontBBox[ -503 -250 1240 750] /FontFile2 9 0 R>> endobj
The Fonts used by the Word document gets embedded into the PDF so the pdf is self-contained.
I used this slide-deck to decypher the PDF instructions.
If you want to prevent the fonts being embedded in the PDF file make sure your Word document makes use of one of the 14 standard typefaces available in PDF viewers, (source Wikipedia)
- Times New Roman > Times (v3) (in regular, italic, bold, and bold italic)
- Courier New > Courier (in regular, oblique, bold and bold oblique)
- Arial > Helvetica (v3) (in regular, oblique, bold and bold oblique)
- Symbol > Symbol
- Wingdings > Zapf Dingbats