I'm just playing about with this and I can't seem to get it to work
quite the way I expect.  I've created two signatures, to match the jpeg
exploit we discussed recently.  My idea is that although the signature
is very small it minimises false positives by being restricted to
graphics files and then looking for the jpeg magic number at the start
of the file.  Since we established the other day that the four byte
sequence that triggers the exploit can't appear in a genuine jpeg this
should be okay.
Anyway, I created signatures in local.ndb as follows...

Exploit.Jpeg.comment.1:5:0:ffd8*fffe0000
Exploit.Jpeg.comment.2:5:0:ffd8*fffe0001

And tried scanning the exploit sample from here
http://www.gulftech.org/?node=downloads
Nothing!
Trying again with --debug I see this message
LibClamAV debug: Type: 501, expected: 514 (Exploit.Jpeg.comment.2)
LibClamAV debug: Type: 501, expected: 514 (Exploit.Jpeg.comment.1)

I only seem able to get this to work by changing the target type in the
sig to 0 i.e.
Exploit.Jpeg.comment.1:0:0:ffd8*fffe0000
Exploit.Jpeg.comment.2:0:0:ffd8*fffe0001

At which point it all works, but surely it should work with a target
type of 5?

BTW.  I tried both scanning the jpg and a message containing it same
result

BTW2. Symantec is now detecting this exploit as Bloodhound.exploit.13





BMRB International 
http://www.bmrb.co.uk
+44 (0)20 8566 5000
_________________________________________________________________
This message (and any attachment) is intended only for the 
recipient and may contain confidential and/or privileged 
material.  If you have received this in error, please contact the 
sender and delete this message immediately.  Disclosure, copying 
or other action taken in respect of this email or in 
reliance on it is prohibited.  BMRB International Limited 
accepts no liability in relation to any personal emails, or 
content of any email which does not directly relate to our 
business.




-------------------------------------------------------
This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170
Project Admins to receive an Apple iPod Mini FREE for your judgement on
who ports your project to Linux PPC the best. Sponsored by IBM.
Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php
_______________________________________________
Clamav-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/clamav-users

Reply via email to