RE: Usefulness of Network Intrusion Detection Systems

["Rob Shein" <shoten () starpower net>]

Comments inline.

> -----Original Message-----
> From: Thomas [mailto:TheTom () UnixIsNot4Dummies ORG] 
> Sent: Thursday, May 27, 2004 3:24 AM
> To: focus-ids () securityfocus com
> Subject: Re: Usefulness of Network Intrusion Detection Systems
>
>
>
> > > Additionally companies do not care much about switches, 
> routers or 
> > > web-servers. Sure they got bad PR if it is compromised or 
> turned off 
> > > but there is no direct lost of money connected with it.
> >
> > Apart from n hours of my time investigating and fixing the problem, 
> > usually at overtime rates? Potential compromise of 
> confidential data? 
> > The cost of having staff sitting around while critical servers are 
> > down?
>
> No problem, the staff is already there and paid. :)

Yeah, but what about the cost of replacing them when they quit, because
they're constantly working overtime without being compensated for it?
Thinking they'll be indifferent about it is a rather pointy-haired attitude,
I feel.  And that's the security/IT staff; what about the rest of the
company, sitting idle and unproductive while being paid?

> > The IDS I run is an integral part of the detection and response to 
> > network threats. Of course I do as much as I can about 
> prevention, but 
> > on a large network where everyone wants to be relatively free, you 
> > will have compromises and attempted attacks; especially from worms 
> > such as Blaster, Welchia, Sasser and Slammer.
>
> You talk about "attempted attacks". Information about several 
> hundered unsuccessful attacks from a worm is no information 
> just noise.

What if it's a worm-infected host on your network?  At that point, even if
every other single machine (I'm thinking Sasser here) is patched, the
attacks are unsuccessful, but it sure would be nice to be able to detect,
identify and find the system in question.  For us, IDS was hugely helpful in
cleaning up, and in determining how Sasser got onto our back network to
begin with.

> > The IDS helped us avoid any network downtime due to Sasser 
> and if the 
> > network is down, the cost of having staff sitting idle 
> mounts up very 
> > quickly indeed.
> >
> > It does take a lot of work to manage, but IMHO it's a lot 
> better than 
> > having no idea what's going on in your network.
>
> Yes, that is right. And I see the value of network based IDS.
> I don't say they are not useful but there use should be 
> limited to an area they belong to. The network, not the 
> applications nor the operating system in general.



---------------------------------------------------------------------------

---------------------------------------------------------------------------