Security Basics
Manipulate PDFs with Malware Jan 20 2013 05:59AM
Andre Silaghi (andre silaghi googlemail com) (3 replies)
AW: Manipulate PDFs with Malware Jan 23 2013 10:32AM
Booth, Daryl (Daryl Booth mobil-isc de) (1 replies)
Re: Manipulate PDFs with Malware Jan 29 2013 07:58AM
Andre Silaghi (andre silaghi googlemail com)
RE: Manipulate PDFs with Malware Jan 23 2013 07:20AM
Simon Thornton (simon thornton info)
Re: Manipulate PDFs with Malware Jan 21 2013 06:55AM
Nick Clark (nick clark-clan com) (2 replies)
RE: Manipulate PDFs with Malware Jan 22 2013 05:42PM
David Gillett (gillettdavid fhda edu)
If I recall correctly the structure of PDF files, elements contained in the file are easily overridden by appending a new value for the (specified) element. So the challenges really are (a) to identify the element to be overridden (and if this is a form, the attacker might only have to do that once for all instances of that form...), and (b) possibly, to hide the fact that the size of the file as opened is slightly larger than the size advertised by the host it was downloaded from.

Tricky, perhaps, and I don't actually know of malware that does this -- but it doesn't sound impossible to me.

David Gillett

CISSP CCNP

-----Original Message-----

From: Nick Clark [mailto:nick (at) clark-clan (dot) com [email concealed]]

Sent: Sunday, January 20, 2013 22:55

To: Andre Silaghi

Cc: security-basics (at) securityfocus (dot) com [email concealed]

Subject: Re: Manipulate PDFs with Malware

Depends on how the PDF is formed. If they are just using an image or flat text, I cannot think of any easy way to do this. If they are using a form, and this barcode has a set attribute field, then you could probably search for the field and replace it with whatever you'd like to.

---

Nick Clark

On Jan 19, 2013, at 10:59 PM, Andre Silaghi <andre.silaghi (at) googlemail (dot) com [email concealed]> wrote:

> Hello everybody,

>

> Let me just explain to you a scenario before I ask my question about

> it. You are starting to download a PDF file including a barcode which

> is used to identify some payment information like the ammount of money

> you have to pay and the receiver, maybe identified by another sequence

> which is included.

>

> Would it be possible to manipulate this barcode easily before or

> during the opening process of the PDF in order to change the payment

> information in a way that the attacker's information is encoded there?

>

> Have you any experience with malware like this?

>

> Best regards,

> André

>

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[ reply ]
Re: Manipulate PDFs with Malware Jan 21 2013 09:31AM
Adam Pal (carpathin wolf gmx net) (1 replies)
AW: Manipulate PDFs with Malware Jan 21 2013 06:06PM
Günther, Sebastian (guenther sebastian googlemail com)


 

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