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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63 views

Some digitally signed pdfs shown as verified in the pdf viewers while others are not

I have two pdf documents: 1 - My class 10 marksheet issued by the CISCE that I downloaded through digilocker. 2 - My Domicile certificate issued and downloaded from the aaplesarkar website. Both ...
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1answer
64 views

Is it safe to view local pdf files in a browser?

When receiving a pdf file by e-mail, the question is how to open it. Browsers are normally quite secure, don't support all pdf features (an advantage in this case) and the viewer/conversion might ...
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0answers
34 views

Burst and rebuild pdf to discard eventual embedded malware

This question deals with how to scan, while i am curious if my acrobat reader DC is compromised but in an isolated container and i pull out the pdf. Is it safe to disassemble the pdf by pdftk burst .. ...
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0answers
95 views

What is the difference between PKCS#7 and CADES, PADES and XADES?

I am newbie in PKI. For signing a pdf documents we are free to consider each pkcs#7 format or PADES format. If I have some misunderstandings, please turn it on for me.
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1answer
2k views

PDF UrlMal-inf[Trj] Virus

When I create PDF file from my particular DOCX file, it gets infected with the virus. But if I create a new DOCX file and create PDF from that, it doesn't get infected with the virus. I have tried ...
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1answer
44 views

Does making a pdf searchable make it more vulnerable? [closed]

I would like to know if making a pdf 'searchable' somehow make it less secure?
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16 views

How secure is pdf password protection? [duplicate]

I'm assuming PDF password protection uses encryption. How secure are the methods used? Can it be easily cracked or is it more in line with modern GPG encryption in terms of strength?
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1answer
438 views

Send GET request from a PDF file

I'm currently working on a security Proof Of Concept where I need to show the danger of opening an unknown PDF file. Internet says that many malwares use Javascript in PDF document (AcroJS) to ...
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0answers
31 views

What source formats are affected by ImageMagick's vulnaribility caused by Ghostscript?

According to https://www.theregister.co.uk/2018/08/23/imagemagick_ghostscript/ ImageMagick's convertion to PDF of arbitrary (user-submitted) documents should not be used because of Ghostscript's ...
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2answers
1k views

Malicious PDF file upload

I have a web server for my customers to upload their PDF files. I have also an IDS/IPS with Anti-Malware license that is between the user and the web server and blocks malicious PDF files from ...
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1answer
674 views

PDF and embedded JavaScript

We have completed a vulnerability and a penetration test. One feature of our application allows for documents to be uploaded, and we allow for PDF documents. Prior to a document being accepted we ...
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2answers
1k views

Is this a safe way to open a PDF file? [duplicate]

I have recieved an email with a pdf file whose content I want, but I'm not exactly sure what the source of it is. In gmail, I have two options: "Download" and "Save to Drive". I'm assuming it means ...
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1answer
77 views

What is the industry standard practice for saving a potentially (likely) malicious PDF for analysis?

I've received an email with an attached PDF which has many signs of being a malicious attachment. Lacking the time and resources to analyze it at the moment, I'd like to store it for later use, and ...
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1answer
79 views

How useful is PDF signing in real world usage?

Background senario: So we had a problem where our system (Alice's shiny widgets) generated a PDF with a quote amount for 10 widgets. Someone (Eve) took the PDF, altered it to increase the price by 20%,...
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0answers
132 views

HTML Form to PDF vulnerabilities

I have a form where the user inputs data. On the back end, I'm taking some of that data and embedding it into a PDF using ActiveReports. I then display it back to the user and save a copy on our ...
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0answers
71 views

Which (FOSS) tools (on Linux) support displaying or verifying digital signatures [closed]

So far I have been unable to find any tools on Linux (preferably FOSS) which will display a digital signature when viewing a PDF file and possibly also allow verification of the validity of that ...
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1answer
106 views

How can I detect and reject potentially unsafe pdf uploads

We develop a web app that will start accepting pdf uploads, which will be stored and distributed to other users. Pdfs seem remarkably unsafe still. How can I scan and reject any pdf that does ...
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1answer
81 views

pdfid analyzing / disarming documents causing infection?

If you analyze or disarm a potential unsafe pdf file using pdfid , will it infect the machine while doing it? Is it the same with peepdf?
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1answer
128 views

Exploit user input being directly inserted into PDF

I'm testing a web application where user input is directly inserted into a PDF file which can then be downloaded. The user input is accepted as is, without encoding or any other modification. This ...
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1answer
24 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. ......
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0answers
106 views

What encryption method is used on macOS Preview.app?

In order to send a file securely, I am going to encrypt/password protect a PDF file with Preview on macOS. Other question(s), such as this one have asked the method of encryption for PDF's in ...
2
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1answer
388 views

Execute Shellcode embedded into a picture? [duplicate]

Somebody told me it is possible to insert shellcode into an image or pdf file and execute the shellcode if the image or pdf file was opened. I know that this could be possible if the application (for ...
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1answer
166 views

Adobe PDF File With Embedded Javascript signature in PAN firewall [closed]

I found many PDFs that are vulnerable, and my Palo Alto firewall categorises them as "Adobe PDF File With Embedded Javascript". And this pdf file contacting a Russian IP address. What should I do? My ...
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1answer
100 views

Is it safe to open “suspect” pdf files in virtual machine? [duplicate]

I became aware recently that Javascript scripts can be embedded in PDF files. Anyway, I have a pdf file which I suspect is not safe to open. I scanned it with VirusTotal and Kaspersky VirusDesk and ...
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0answers
372 views

Security risks with pdf files in object tag at client/server side

This is my situation: a user uploads a pdf file to my server. The data travels encoded in base64 (like a regular input in a form). The base64 is saved in one particular file on my server. Now, another ...
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1answer
616 views

Does embedding images in PDF retain metadata?

I have a PDF file which I can select images to embed in. The customers are not technical so I do not want them to remove metadata themselves (e.g. GPS location of photos, etc). Will the PDF ...
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1answer
1k views

Extract malicious code from PDF file

I've a PDF file that contains some malicious code; when opened the processor usage maxes out and the fans run at full rpm. The pdfid.py produces the following output: PDF Header: %PDF-1.7 obj ...
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1answer
242 views

Deobfuscating Javascript Code in a Malicious PDF

I'm currently working on a project to look at how PDFs are infected, and what the malicious code found in these documents do. The malicious code is obfuscated, and I've tried a variety of methods ...
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1answer
1k views

Why won't pdf2john extract the password hash of this encrypted pdf? Getting blank results

New to the community, and to JtR and Hashcat as a whole, but after searching for a few days I couldn't find a solution to this specific problem. I have a password protected PDF file that I'm trying ...
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2answers
5k views

Can a computer get infected with malware by viewing a PDF online?

Is it possible for a computer to be infected by viewing the link to a PDF file without downloading it? For example, if I opened a link on a website such as www.wordpress.com/somepdfFile.pdf (not a ...
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1answer
2k views

What's the risk in downloading a .pdf from a phishing email?

I've received an email which is an obvious phishing attempt. However, a .pdf has been attached which I want to open, just out of curiosity! What are the risks in downloading .pdf files from unknown ...
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0answers
31 views

How can I establish origin/ authenticity of a electronic document

Scenario: PartyA had put up an online offer on PartyB's certain product, if I bought the product through PartyA's channel then I shall be entitled to an specific gift/reward if PartyB approves my ...
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2answers
822 views

What is a secure method to send pdf files with private information? [duplicate]

An employer wants me to send an i-9 form, which has my social and date of birth, via e-mail to their HR department. This seems quite baffling to me why they would want me to just send the form in ...
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2answers
301 views

How to safely store infected PDF file that I have created?

I have two computers, computer A and computer B. With computer B I created an infected PDF file using setoolkit following this youtube toturial. The file is on a VM right now. On computer A I have a ...
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1answer
54 views

How is it secure to open documents with embedded/linked fonts and images

There were some kernel exploits and CVEs (for example ms11-087 and CVE-2017-8682) about fonts. And there were some malware campaigns like duqu which used zerodays in fonts embedded into docx files. I ...
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3answers
3k views

Can you directly view a malicious PDF on Linux?

There have been questions on safe viewing of malicious PDFs on OS. I would like to know if it's okay to directly open them to view them in a Linux OS because the OS is said to be secure and malware-...
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3answers
152 views

Properties on PDF file

I have a PDF file which, when going via "Properties" shows no data -- for example no mention of the author of the file. is thre any way i can unlock such information.
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1answer
461 views

Publish a PDF on a website with MD5 Hash [closed]

I want to publish PDF documents on my website. I calculated the MD5 Hash of the file before uploading it. I want to provide this hash so that the downloader can check if the file is okay. What is the ...
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1answer
356 views

Is CSRF possible against a PDF download that requires cookie auth?

A site I work on has a link that downloads and opens a PDF containing sensitive user data. The user's authentication cookie is checked serverside to ensure they have access to the data before ...
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2answers
22k views

How to know if a PDF file is infected?

I'm afraid to open a PDF book. When checking the file via pdfid, I get this: PDF Header:% PDF-1.6 obj 4175 endobj 4174 stream 3379 endstream 3379 xref 0 trailer 0 startxref 1 /...
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0answers
52 views

Secure deployment of xpdf on production

I have an application, which needs the functionality of converting PDF documents to text documents, and then parse them to retrieve information. I am using xpdf utility pdftotext to achieve that. I ...
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1answer
132 views

What's a file format that is user-friendly and text-friendly but _largely_ non-editable?

Recently, I'm coming across more and more places that use PDF files as a non-editable format to ensure that the data in it is not altered in any form. (Whether that is a good idea or not is another ...
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1answer
4k views

How To Crack The PDF Password? [duplicate]

I need to edit and merge some pdf files which are asking pasword. How can I crack the password?
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1answer
598 views

Self signed signature in PDF

I am asking for a very simple "dumbed-down" answer for a newbie. Using Adobe Acrobat I can create a self-signed certificate and sign a document as anybody. I can use anyone's name and anyone's ...
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2answers
224 views

PDF parser and OPcodeExtraction [closed]

I'm performing an university project on malware detection. Specifically I need: - extract javascript from a PDF, ...
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1answer
128 views

Does Adobe Acrobat Reader DC upload opened PDF files?

I'm wondering if Adobe Reader DC uploads all the PDF files it opens to the Adobe Cloud, even if you have not signed up for the cloud. I am not a fan of Adobe and generally do not install Adobe ...
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2answers
5k views

What is the risk of a PDF “infected” with BC.Pdf.Exploit.CVE_2017_3033?

ClamAV (detection version 20170623) detects BC.Pdf.Exploit.CVE_2017_3033 in quite some PDF files. I wonder if this is not a false-positive because no other engines detect such "infection". The CVE ...
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3answers
738 views

Is a PDF creating service vulnerable for injection of malicious code

We have a report in our web application that being shown in tabular format in HTML. This report has the provision to be downloaded as PDF by clicking the download as PDF button. The question is about ...
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1answer
186 views

How can the geometry of a JPG 2000 image within a PDF execute code when opening it in Adobe Reader?

I work in incident handling/threat analysis and our events are based on Snort rules built from CVEs. I'm researching a particular event and I'm wanting to understand what exactly the vulnerability is, ...
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1answer
133 views

Excel vs PDF protection [closed]

A recent requirement been received to automatically email Excel documents to customers. The customer would then amend the Excel file and send it back. The current options are to password protect the ...