Ethical Hacking

Learn to find vulnerabilities before the bad guys do! Gain real world hands on hacking experience in our state of the art hacking lab. Course designed and taught by expert instructors with years of penetration testing experience. 12 student maximum in every class. Certification attempt included in every package.
Computer Forensics Training at InfoSec Institute

Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse at your organization so that it never happens again. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors.




Network Security Snort-Users
[Top] [All Lists]

Re: [Snort-users] writing virus signatures

Subject: Re: [Snort-users] writing virus signatures
Date: Wed, 25 May 2005 15:28:06 -0500
So if Snort can clean out the bulk of the traffic thats infected with
the common virii then the saving on resources is enormous for me. This
does not mean that I do away with the AV servers but that the AV servers
work as specialist AV cleaners and Snort works as the general AV cleaner.

How are you planning on doing this?  flexresp?

Now comes the part of looking into zip files which is where we still
need ClamAV and other AV solutions. My question is that why isn't there
 a unique identification string in the zipped payloads of the
virii/worms? Why do attachments need to be unzipped before being
examined since no two files can have the same zip file?

Writing signatures against a zip file, rather than against the payload
of the viri is possible I suppose, but in practice probably not a good
idea.  I think you would end up with a AV signature database larger
than anybody would want to manage, probably a high number of false
positives, and a signature that would be trivial to circumvent.

A lot of times viri have double extensions, which attempt to mask the
real extension i.e. .zip.exe would look like .zip.  In this case you
would not need to unzip anything as the file is actually an MZ or PE
executable for which you could create a valid signature.

Regards,

Will


-------------------------------------------------------
SF.Net email is sponsored by: GoToMeeting - the easiest way to collaborate
online with coworkers and clients while avoiding the high cost of travel and
communications. There is no equipment to buy and you can meet as often as
you want. Try it free.http://ads.osdn.com/?ad_idt02&alloc_id135&opÌk
_______________________________________________
Snort-users mailing list
Snort-users@lists.sourceforge.net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list

<Prev in Thread] Current Thread [Next in Thread>