Trouble reading PDF file? Solution to reading malformed damaged PDF files

Sometimes PDF files can get scrambled and you are stuck not being able to open a PDF file. Most PDF software cannot open the test file below. Adobe Acrobat Reader issues the pop-up screen could not open because it's not a supported file type or the file has been damaged.

Solution: 

Get XpdfReader PDF software which can open a malformed PDF files!


For more information about internal structure of PDFs

1. Basic Structure of PDF documents | Automate PDF (automatizarpdf.com)

2. In-depth exploration of PDF document structure - losLab Software Development

Test 1:

In the following sample file, the file starts with malformed PDF file signature 

%P!F- which is incorrect and should be %PDF-, as seen in FRHED editor. 

XpdfReader is the only app I came across that could open this file with this first malformed change.

Test 2: 
 
Then I remove leading angle bracket < where there should be two for <<Lineralired, and it opened! 

Source

The original unadulterated file header is

%PDF-1.5%<bh:e2><bh:e3><bh:cf><bh:d3>10 0 obj\<</Linearized 1/L 105981/O 12/E 101484/N 1/T 105677/H [ 502 173]>>endobj

Opened Malformed File

For more information about internal structure of PDFs

1. Basic Structure of PDF documents | Automate PDF (automatizarpdf.com)

2. In-depth exploration of PDF document structure - losLab Software Development

Example of absolute minimal PDF file contents "Hello World", copy and pasted into FHRED.

%PDF-1.1
1 0 obj
<< /Type /Catalog /Pages 2 0 R >>
endobj
2 0 obj
<< /Type /Pages /Kids [3 0 R] /Count 1 >>
endobj
3 0 obj
<< /Type /Page /Parent 2 0 R /MediaBox [0 0 200 200] /Contents 4 0 R /Resources << /Font << /F1 5 0 R >> >> >>
endobj
4 0 obj
<< /Length 44 >>
stream
BT
/F1 12 Tf
72 100 Td
(Hello World) Tj
ET
endstream
endobj
5 0 obj
<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>
endobj
xref
0 6
0000000000 65535 f 
0000000009 00000 n 
0000000056 00000 n 
0000000107 00000 n 
0000000212 00000 n 
0000000310 00000 n 
trailer
<< /Size 6 /Root 1 0 R >>
startxref
380
%%EOF

Here's Hello World.pdf opened