Using Magic Values along with filetype to find malicious files (was RE: Google Malware Search)

["Debasis Mohanty" <debasis.mohanty.listmails () gmail com>]

Nice .. Realy nice pointers H.D. !! :)

I was thinking on different lines, possibly one can use magic values of
different types of executables along with "filetype:" keyword. 

For Example: 
EXE -- 0x5A4D
NT -- 0x4550 
OS2 -- 0x454E 
OS2 LE -- 0x454C
VXD -- 0x454C

Now, if one has to search for malicious binaries in the form of .scr, .com
or .pif etc then (s)he can issue the following search keywords - 

"intext: signature: 5A4D" filetype:scr
"intext: signature: 5A4D" filetype:pif
"intext: signature: 5A4D" filetype:doc

or (without using "intext")

signature: 00004550 filetype:scr
signature: 00004550 filetype:doc


The results can be narrowed down using a signature database like the one
being used here - http://metasploit.com/research/misc/mwsearch/sigs.txt

Similar results can also be achieved using search keywords for specific
details in a PE / LE header. For example - 

Search for ["intext: Image File Header" filetype:scr] gives almost the same
result as ["intext: signature: 5A4D" filetype:scr]


-d (aka t)
www.hackingspirits.com


-----Original Message-----
From: full-disclosure-bounces () lists grok org uk
[mailto:full-disclosure-bounces () lists grok org uk] On Behalf Of H D Moore
Sent: Monday, July 17, 2006 10:29 AM
To: full-disclosure () lists grok org uk
Subject: [Full-disclosure] Google Malware Search

http://metasploit.com/research/misc/mwsearch/?q=bagle

Enjoy,

-HD

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