SDF, please!
"We're under a targeted malware attack!", a friend of mine yelled into the phone. "We are getting lots of oddly named PDFs, attached to personalized emails, sent only to certain employees in our firm!". From some past experience with chewing through our nasty malware repository here at SANS ISC, I had learned a thing or two about malicious PDFs, so I agreed to take a look.
One hour later, it was clear that the PDFs in this case were free of any exploit, completely harmless, and contained only the average "I AM A COUSIN OF THE LATE ZESKEKE NGAGWENE" type of Nigerian 419 (advance-fee) fraud spam.
But the whole episode gave me pause. It really looks like the past two years of never ending new waves of PDF exploits have degraded PDF in the mind of every security analyst to a level somewhere at par with ANI and SCR files: No matter what it claims to be, it ain't nothing good.
I very much agree with Stephen Northcutt's comment in SANS Newsbites two months ago. He asked: "Is there an alternative to a .pdf? It was supposed to be a printable image of what you saw on the screen. At least that was the idea 15 years ago. It should not need "launch" functions to do that. Do you remember five or six years ago, you weren't supposed to send an excel spreadsheet or a word document because they might contain malware, you were supposed to send a .pdf. Guess that has changed!"
Time for SDF - the Safe Document Format. You know, one that just supports pixels in various shades of gray, and does not need to include the ability to play a movie in 3D accompanied by surround sound. Just a nice plain document that can be opened, read and printed, without any of the nagging feeling of dread that nowadays accompanies clicking on a PDF.
Anyone?
Comments
roseman
Sep 2nd 2010
1 decade ago
anonymoose
Sep 2nd 2010
1 decade ago
Maybe we could bring back PostScript, but that's turing-complete, and since they can't sandbox Reader I doubt they can sandbox PostScript.
Steve Shockley
Sep 2nd 2010
1 decade ago
http://en.wikipedia.org/wiki/PDF/A
Also, PDF was always about more than "a printable image of what you saw on the screen.". The troubles really started when the singing and dancing extensions were added to later versions and software.
A valuable contribution to security would be an open source PDF reader that did not implement the dangerous stuff.
And Steve: Postscript has had very dangerous features (worse than Turing-completeness) for a long time. Doesn't mean they need to be implemented! SafePDF built on top of SafePostscript with sufficient backward compatibility ... One could hope.
A valuable contribution to security would be an open source PDF reader that did not implement the dangerous stuff.
And Steve: Postscript has had very dangerous features (worse than Turing-completeness) for a long time. Doesn't mean they need to be implemented! SafePDF built on top of SafePostscript with sufficient backward compatibility ... One could hope.
Rex
Sep 2nd 2010
1 decade ago
its sad that one of the more reliable formats has been retooled to continuously add complexity. adobe reader is just gigantic lately lol.
joco
Sep 2nd 2010
1 decade ago
Philipp
Sep 2nd 2010
1 decade ago
Poch
Sep 2nd 2010
1 decade ago
cynic
Sep 2nd 2010
1 decade ago
@cynic, but how can I use Comic Sans in my important document if it's in plain text? :-)
Paul
Sep 2nd 2010
1 decade ago
No Love.
Sep 2nd 2010
1 decade ago