Error opening PDF file from attachment?

Question

PDF

When I receive mail with a PDF attachment, when I try to open it from view mode - by double clicking, the STDU Viewer application is launched, which I have configured to view pdf files. Next, the application tries to open the file and an error occurs: "Unable to open file: (path and name). The file is corrupted or has an unsupported format."
The attempts made to solve the problem did not lead to positive results:
1. Reinstalling the application. The application opens Other PDF files safely.
2. Copying a file from a letter to a hard drive also changed the situation.
3. Forwarding an attachment to another mailbox - the attachment also does not open.
4. When sending a letter, the addressee sends a copy for additional. box. Opening a file on the same computer from a browser does not cause a problem.
5. Disabling Avast antivirus did not bring positive results.
Has anyone encountered such a problem?
According to my assumptions, it is Outlook 2013 that "kills" pdf files, for unknown reasons. Files of other extensions sent in the letter - open without problems.
My system is Windows 8 x64

Answer 1

< Navigate to the folder with the damaged PDF file. Right click on it and select Rename. Type any other filename and press "Enter". Sometimes, simply renaming can fix corrupted PDFs.
< Make sure your Adobe Reader is in working order. Open any other PDF files on your hard drive to make sure the problem is not coming from your Adobe Reader. If this happens, reinstall Reader from the Adobe website for free.
< Update Adobe Reader. Launch Adobe Reader from the Start menu under All Programs. Click on the "Help" tab and select "Check for Updates..." Follow the instructions on the screen to complete the update installation.
Or try recovery software, in my opinion this is the best https://www.repairtoolbox.com/en/pdfrepair.html PDF Repair Toolbox

Answer 2

There is a strong suspicion that the PDF itself is not formed correctly. Save to disk and check the file for virustotal.