Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 63.0.3239.132 
- Operating system and its version: Windows 10
- PDF.js version: using your official demo project
- Is a browser extension: No

Steps to reproduce the problem:
1.  Just load attached pdf
2.

What is the expected behavior? (add screenshot)
[E-WG18_105147.pdf](https://github.com/mozilla/pdf.js/files/1634833/E-WG18_105147.pdf)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/29802177/34986271-3ca71a5c-fab7-11e7-95e8-1739dda3cd04.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

const header = file.peekBytes(4);
  if (
     header[0] >= 1 &&
    
    
     header[3] >= 1 &&
    header[3] <= 4
  ) {
    return true;
  }
  return false;
}
function getFontFileType(file, { type, subtype, composite }) {
  let fileType, fileSubtype;
  if (isTrueTypeFile(file) || isTrueTypeCollectionFile(file)) {
    if (composite) {
      fileType = "CIDFontType2";
    } else {