Re: http_inspect message

[Mario Remy Almeida <mario.almeida () gmail com>]

Hi Martin

Actually I company web site is under attack, there are trons of new
connection form different IPs. At present with iptables I have set 25
connection p/s (--state NEW) after this server seems to be normal.
I recommended to snort to my man agent to give a try, with the
subscription we download the rule sets too. but now I am lost. I have
enable all the rules from dos and ddos rule files. Let me enable all
the rules from backdoor.rules and watch for alerts.

You mean signatures, that is the rule set right?

On Sun, Sep 18, 2011 at 10:51 PM, Martin Holste <mcholste () gmail com> wrote:
> No, you are not under DOS attack.  This is a very common message from
> the http preprocessor.  Actually, the http preproc will create many,
> many messages like this, almost all of which can be safely ignored
> until you are more familiar with Snort.  I recommend that you ignore
> alerts from all of the preprocessors until *AFTER* you have mastered
> the regular rules.  By this I mean worry first about any signatures
> which have the "trojan-activity" classification or are SQL injection
> signatures.  Also, take this opportunity to add a heartbeat signature
> so you'll know for sure if you're dropping packets (you can safely
> skip this step if you are monitoring a link with < 100 Mbit/sec).
> Once you've your normal ruleset tuned and have responded to the
> malware  infections that you probably just found now that you've got
> something other than AV keeping an eye on things, you can proceed to
> check out the alerts generated by the preprocessors.
>
> On Sun, Sep 18, 2011 at 12:10 PM, Mario Remy Almeida
> <mario.almeida () gmail com> wrote:
> > Dear All,
> >
> > I am new to snort.
> > I get lots of this message
> >
> > [119:14:1] (http_inspect) NON-RFC DEFINED CHAR [**] [Classification:
> > Potentially Bad Traffic] [Priority: 2] {TCP}
> >
> > Dose it mean I am in kind of DOS attack? can someone give me some tips
> > if I need to analyze it more or should I block such IPs?
> >
> > ------------------------------------------------------------------------------
> > BlackBerry&reg; DevCon Americas, Oct. 18-20, San Francisco, CA
> > http://p.sf.net/sfu/rim-devcon-copy2
> > _______________________________________________
> > 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!

------------------------------------------------------------------------------
BlackBerry&reg; DevCon Americas, Oct. 18-20, San Francisco, CA
http://p.sf.net/sfu/rim-devcon-copy2
_______________________________________________
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!