Re: How to decide which rules should be enabled.

[Tony Robinson <trobinson () sourcefire com>]

Hi there,

The question around rulesets is one that is very easy to ask, and
exceptionally difficult to answer. It really requires knowing your network
and enabling rules for things that concern you. that is going to differ
from place to place and snort deployment to snort deployment. One person
may be concerned about p2p traffic, or rules that violate corporate policy,
while another may be concerned about botnet CNC rules.

Something that may help you build a good rule baseline is the program
pulled pork. (link to the readme:
http://code.google.com/p/pulledpork/source/browse/trunk/README?r=225) The
program will pull down the latest available rules from snort.org and allows
you to easily build a ruleset based off three base policies: Connectivity
over Security, Balanced, and Security over Connectivity. From there you can
pare down a rule-heavy ruleset, or bulk up one of the smaller rulesets to
meet your needs.

Another recommendation I can make is signing up to the SANS @risk
newsletter. Every Thursday, SANS puts out a newsletter of the top exploits
and malware seen out in the wild, with the help of our very own VRT
(Vulnerability Research Team). Under each vulnerability is an associated
snort SID (or in some cases, multiple SIDs), and an associated ClamAV
signature for detecting the exploit or malware. Best of all, this is a free
resource.

While these aren't definitive answers to your question, they are a very
good start to building a good rule set.

In regards to your question for testing snort, there are many ways of doing
that. Snort has a built-in -T parameter you can use to test the snort.conf
file and ensure that everything is "sane" and that snort will at least
start up.

In terms of testing whether or not snort is actively sniffing traffic off
the wire, a good trick is to create a file called local.rules, include it
in your snort.conf file and create a simple rule such as:

alert icmp any any any (message:[your message here] sid:1000000; rev:1;)

and trying pinging something your snort sensor has visibility on. If you
get alerts, it is a good sign that snort is working. This is usually a
setup step specified in some of the snort install guides on snort.org.

Hope this helps,

-Tony

On Wed, Jul 18, 2012 at 3:47 AM, Bravo Snipper <snipperbravo () yahoo com>wrote:

> Hi
> After snort installation now how can we decide that which rules should be
> enabled or we should enable all the rules given by snort. Can any one
> please share some  tutorial regarding this aspect of snort configuration.
>
> Plus can any one name some standard set of tools to  test snorts setup.
>
> regards.
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> 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=snort-users
>
> Please visit http://blog.snort.org to stay current on all the latest
> Snort news!



-- 

 Tony Robinson
Security Consultant I
SourceFIRE Professional Services Division

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/

_______________________________________________
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=snort-users

Please visit http://blog.snort.org to stay current on all the latest Snort news!