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Questions tagged [pdf]

Portable Document Format (PDF) is an open standard for electronic document exchange maintained by the International Organization for Standardization (ISO). Questions can be about PDF specific malware or protections.

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59 votes
11 answers
91k views

How to safely view a malicious PDF?

I have a PDF with important information that may contain malware. What would be the best way to view it?
user avatar
85 votes
3 answers
298k views

Can a PDF file contain a virus?

Could a PDF file contain any type of malware?
user avatar
161 votes
14 answers
18k views

What is the safest way to deal with loads of incoming PDF files, some of which could potentially be malicious?

As an investigative journalist I receive each day dozens of messages, many of which contain PDF documents. But I'm worried about some of the potentially malicious consequences of blindly opening them ...
Tom the journalist's user avatar
72 votes
3 answers
38k views

What security scheme is used by PDF password encryption, and why is it so weak?

Many PDFs are distributed as encrypted PDFs to lock out some of their functionality (eg printing, writing, copying). However, PDF cracking software is available online, which usually cracks the PDF ...
March Ho's user avatar
  • 1,685
46 votes
5 answers
83k views

How to scan a PDF for malware? [closed]

Can anyone suggest an automated tool to scan a PDF file to determine whether it might contain malware or other "bad stuff"? Or, alternatively, assigns a risk level to the PDF? I would prefer a free ...
D.W.'s user avatar
  • 99.1k
20 votes
4 answers
8k views

Detecting and preventing 'phone home' behavior in PDF files

I have received several PDF documents via email from someone I do not trust. I need to read the documents and respond to them. They are not encrypted. I want to make sure the documents are ...
Tim's user avatar
  • 201
20 votes
1 answer
49k views

How can I extract the hash inside an encrypted PDF file?

As long as I know, the encrypted PDF files don't store the decryption password within them, but a hash asociated to this password. When auditing security, a good attemp to break PDF files passwords ...
Sopalajo de Arrierez's user avatar
19 votes
2 answers
6k views

Effectiveness of flattening a PDF to remove malware

I'm currently looking at ways to prevent malicious PDF files at the network boundary. This will include virus scanning - but there are known limitations to that. I see a common approach is to flatten ...
symcbean's user avatar
  • 18.5k
7 votes
2 answers
21k views

Cracking a password Protected pdf file using John the ripper

What exactly happens after I provide the hash from the pdf file to John for cracking the password? Does John extract just the password hash from the file and work on it, or is there something else?
rats20's user avatar
  • 119
7 votes
4 answers
14k views

How to detect malicious JavaScript in a PDF file?

Is having any JavaScript in a PDF file by definition dangerous or is it only dangerous when specific functions (for example eval) are used inside a PDF, in which case, what JavaScript functions are ...
Bob Ortiz's user avatar
  • 6,337
20 votes
3 answers
38k views

How can I tell if a PDF file I was sent contains malware?

I was emailed a PDF file by a family member. I have reason to suspect that it was given to said family member by someone who would like nothing more than to infect me with a Remote Access Trojan. How ...
user158844's user avatar
12 votes
1 answer
8k views

What are the security risks associated with PDF files?

What are the security risks associated with PDF files? There is, of course, the general risk associated with any type of file: that whatever application is used to read it will have a bug that can be ...
RockPaperLz- Mask it or Casket's user avatar
8 votes
1 answer
3k views

PDF file encrypted with my password, does that mean my password is stored in plaintext?

Every month, I receive an encrypted Portable Document Format (PDF) file with my payslip. I can open the file for reading with my password. Without providing my password, I cannot open the file at ...
gerrit's user avatar
  • 1,830
5 votes
1 answer
2k views

How strong is PDF security/encryption?

I want to securely convey a PDF document containing sensitive information from my system to another system. The latter is operated by a different person, whom I trust. However, this person does not ...
no.human.being's user avatar
4 votes
2 answers
10k views

Removing malware from a malicious PDF file [duplicate]

I have analyzed a large PDF using Didier Steven's pdfid tool. I get the following result: Now that I know there is malicious content in the PDF, what can I do to remove it? I would still like to view ...
Mike's user avatar
  • 141
4 votes
2 answers
3k views

How to remove meta and sensitive data from PDF file?

I've some PDF files generated from different sources (such as web-browser, Photoshop, etc.) on Unix. How do I make sure PDF doesn't contain any sensitive information such as IP address, OS, user name,...
cicada's user avatar
  • 43
3 votes
1 answer
849 views

PDF Documents in Browser 2020

I have a project where I would like to allow a user to view a document (PDF) in their browser by clicking on a link or thumbnail of the file. They would be able to download said file. Ive just begun ...
FamousAv8er's user avatar
1 vote
1 answer
74 views

Can I describe the PDF's certificate-based signatures using W3C's DSIG Core?

Can I map the specialized specifications of PDF's certificate-based signatures into the [XML DSIG Core] standard? I'm imagining PDF as an "XML file analog", to be mapped into the W3C's ecosystem. ......
Peter Krauss's user avatar
0 votes
0 answers
48 views

John the Ripper [duplicate]

I've already cracked a PDF with pdf2john but it doesn't show the password. What could be the problem? (The password isn't blank.)
Márton Környei's user avatar