Bug#698456:

[Tisne Aurelien]

I reproduce this bug: some black squares overlap textual content. I 
cannot provide you the document. This is a bill containing private 
information from a water provider.
I have the same result using evince, gimp, nautilus, xournal.
I have no problem using xpdf, emacs, ghostscript.

result of pdfinfo:

Title:          Facture
Subject:        No Subject
Keywords:       None
Author:         Veolia EAU
Creator:        Docapost Edocuweb
Producer:       [ClibPDF Library 2.02-r1-2] 302j AIX 4.3
CreationDate:   Thu Sep 11 20:49:15 2014
ModDate:        Thu Sep 11 20:49:15 2014
Tagged:         no
Pages:          2
Encrypted:      no
Page size:      595 x 842 pts (A4)
File size:      235964 bytes
Optimized:      no
PDF version:    1.3

result of pdffonts:
name                                 type              emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
Helvetica                            Type 1            no  no no      11  0
Helvetica-Bold                       Type 1            no  no no      12  0

Debian GNU/Linux 7.6 (wheezy)
evince 3.4.0-3.1

Hope these information can help.