PDF documents & URLs: update
I've written before about PDFs with URLs used in social engineering attacks (TL;DR: nowadays, it's more likely you'll receive a malicious PDF that just contains a malicious URL, than a PDF with malicious code).
Since then, I've had a couple of questions about such PDFs where the URL is stored indirectly. Let me give you an example.
I'm using pdfid.py to do a first check of the pdf (I'm using option -n to suppress counters that are equal to 0):
You can see that name /URI appears twice: this is a strong indication that the PDF contains a URL.
Let's extract the values for name /URI with pdf-parser.py:
Instead of extracting the URL, we see that value "18 0 R" was extracted. 18 0 R is a reference to an object with id 18 and version 0.
pdf-parser's option -o can be used to look at this object:
By default, pdf-parser displays the dictionary of an object, but not the data. To view this data, use option -w:
Now we can see that object 18 is just a string: the URL we wanted to extract.
Didier Stevens
Microsoft MVP Consumer Security
blog.DidierStevens.com DidierStevensLabs.com
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www
Nov 17th 2022
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EEW
Nov 17th 2022
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qwq
Nov 17th 2022
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Nov 17th 2022
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isc.sans.edu
Nov 23rd 2022
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isc.sans.edu
Nov 23rd 2022
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isc.sans.edu
Dec 3rd 2022
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isc.sans.edu
Dec 3rd 2022
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<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.
<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
isc.sans.edu
Dec 26th 2022
5 months ago
isc.sans.edu
Dec 26th 2022
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