Network Intrusion Detection and Prevention? 264
c0dyd asks: "Lately, computer attacks have gained much popularity in the news; however, it is not often that we hear of new software, hardware or 'appliances' that combat malicious code attacks and data intrusions. Obviously, the need is present. I've searched thoroughly for network intrusion detection and prevention systems, but the choices and technologies seem somewhat limited or proprietary-- Snort appears an obvious open source solution for intrusion detection but many users many find it lacking in intrusion prevention capabilities. What do you, the experienced network admin, use for detecting intrusions on the network and how does your network react to those intrusions?"
ASL (Score:2, Informative)
You can balance FLOSS and proprietary techs with something like Astaro Security Linux [astaro.com]. They do appliances or standalone software.
Re:ASL (Score:2, Funny)
You mean: 43/m/moms basement
Don't underestimate just paying attention. (Score:5, Informative)
So, don't underestimate the usefulness of watching your network traffic graphs. With rrdtool it's pretty easy to pull out information and average it. For example, we watch not only our overall 95th %ile utilization, but also rank each user based on their utilization. If use suddenly goes up, increasing their rank, it's probably something we should look at. It's been extremely effective for detecting open HTTP proxies, SMTP relays, and people compromised with various vulneribilities.
Sean
Re:Don't underestimate just paying attention. (Score:5, Insightful)
Any good intruder knows to be quiet and spread their attack out over hours or days. Hence they are practically invisible to any sort of bandwidth analysis, until they start downloading larger amounts of your data (at which point it is often too late).
Don't underestimate what you already have (Score:4, Insightful)
What is generally lacking is a policy (which, sadly, security is mostly about) and a concrete idea of what to do when an 'attack' is detected.
And people then buy an expensive new IDS, or spend time to implement one, or whatever. Think it's exciting for a while. And then I come back 3 months later and it's turned off in the corner.
And in the meantime people aren't exploiting the information they already have. Not just the bandwidth graphs but firewall logs, system logs, etc. I personally would recommend finding an event correlation system (anyone know of a good open source one?) along the lines of Netforensics or the former Protego and implementing
IPS -- I haven't had enough personal experience with an in-line IDS to make even a remotely intelligent comment. I like the idea of such a platform but it (as MJR frequently points out) falls foul of being an 'allow everything not specifically denied' platform and thus limited. This is not an outright condemnation, since otherwise you run into best being the enemy of good, but it's something to be considered...
Monitoring is expensive (Score:4, Insightful)
I set up my scripts so I am emailed ONLY on new activity not seen before. So I find ways to silence minor attacks/alerts which does not interest me in conjunction with finding automatic ways to react on attempts.
I can recommend this setup:
Enough is said about this. Absolutely needed, but useless without intervention. Oinkmaster is nice to use for automatic downloading of new rules.
Perl script for iptables/ipchains. Fast and easy to set up, however any decent firewall will do. Narc allows for user-customization/hacking, which is a plus for those who wants to learn ipchains/iptables and do more advanced stuff than a GUI can offer. I like to fiddle with the rules myself for outgoing packets, which very few firewalls supports. It's nice to know your computer is not sending out traffic you don't know what is. By blocking everything outgoing by default, I will catch stuff in the logs and adjust the rules when I know what it is (not recommended while in production).
Blocks hosts temporarily and permanently based on SSH-logs, snort-alerts and firewall-logs. Nice and easy to extend even if you don't know perl, but have patience to test alot. The maintainer is cool about accepting patches. Yes, you need a list of hosts to never block, and yes a dedicated cracker can spoof IP addresses to DOS you. However, I'll deal with that when somebody does just that. It depends how important your service is I guess.
I set up Samhain to email me of EVERY change in the root filesystem. However, I run Samhain with the silent option just after every upgrade at night. So upgrades are done automatically and silently without alerting me (Debian Stable - Sarge).
It's in the Debian-tree. Can't hurt to use more than one checker. This one is less spammy than Samhain and checks for other kinds of signatures in the system.
This might seem much, but I consider it a bare minimum for an install I'm not going to watch over continuously. Running Linux doesn't make you secure, and even with all this, I know I'm still vulnerable to:
A) Crackers hacking over time. Little by little they may do a portscan and find out enough to do a:
B) Full-scale successful attack. Reactive firewalls just won't stop it, and then you're cracked.
C) DOS. Automatic blocking based on IP and DSL-connection is just not enough to stop DOS and DDOS.
However, with a hardware firewall in front, I feel a bit more secure..
One interesting project is a firewall based on snort: Hogwash [sourceforge.net]. The project is in need of maintainers though. However the idea is cool: To block based on snort-alerts in real-time. This can actually be useful to block intrusions before they can do harm other than DDOSing. I for one will accept the increase in latency if it means my network is that much more secure. I really hope this one will take off one day.
How do I do my job? (Score:5, Funny)
Re:How do I do my job? (Score:5, Insightful)
Asking Slashdot is as good a way as any to reach a wide audience and get a handful of good advices amongst the hundreds of trolls. All it takes is asking, and you never know what precious tidbit of information you might get.
Re:How do I do my job? (Score:2, Funny)
Or how long you'll have to sort through the trolls/awful jokes to find it
Re:How do I do my job? (Score:2)
NV ActiveArmor (Score:4, Interesting)
ActiveArmor Firewall supports stateless and stateful inspection, Web-based management, pre-defined security profiles, port block filtering, remote administration, and provides an easy-to-use set-up wizard. In addition, ActiveArmor Firewall has anti-hacking features such as anti-IP-spoofing, anti-sniffing, anti-ARP-cache-poisoning, and anti-DHCP server-important security controls for corporate network environments. In a corporate setting, an end-point firewall (such as a desktop firewall) with anti-hacking capabilities can reduce the internally originated security breaches, and can inhibit desktops from generating unauthorized traffic. The result is improved overall security, with reduced requirements from the IT staff.
Again, I'm not sure if it's what you're looking for, but it's at least a very interesting product.
bad for a server! (Score:2)
"Hey, Bob.. maybe it's this new motherboard we put in to the DHCP server that's causing the problems."
Just wait, it'll take out the DNS server next and maybe a mail server, just to show you who's boss.
Ethereal (Score:5, Funny)
Re:Ethereal (Score:2)
Re:Ethereal (Score:2, Funny)
Re:Ethereal (Score:3, Funny)
Re:Ethereal (Score:3, Interesting)
"Ethereal activity" was "a change in any MD5 signature or file-size for any file on the web server"..
"trained monkey" was a bunch of 24x7 operators (no offence guys.. I'm not making the comparison - just emphasising the distinction)..
"shell script" and "flash the screen red" were still a shell script, and
Re:Ethereal (Score:2)
My complaint about intrusion detection devices. (Score:5, Informative)
The one feature I'd look for in an intrusion detection device is that it can quickly escalate a detected intrusion attempt to real people (through email, phone, calls, etc).
For real enterprise needs, companies like counterpane [counterpane.com] not only install the intrusion detection devices; but offer services that monitor them just like the physical alarm companies do.
Re:My complaint about intrusion detection devices. (Score:2, Insightful)
All of these logs are history. Fortunately I'm running Linux and 99% of these probes and attacks are of little interest and are no threat.
Now, when you get a tool that will tell me when at attack is about to happen, that's when I want to know about that tool. Especially if it can not only give me advance warning, but warnings appro
Re:My complaint about intrusion detection devices. (Score:3, Insightful)
All too often I look back at month old logs and see "hey, that's cool, somone was trying to hack us"
This is why you need to review your logs on a daily basis, or at the very least keep a monitoring program of some kind open that you check once in a while throughout the day. Ideally you've got someone who's en
Festival text to speech (Score:3, Funny)
tail -f
Re:My complaint about intrusion detection devices. (Score:3, Insightful)
"real enterprise" doesn't need another log parser tied to an email notification service. It needs insurance. It needs another company to pass the buck to when they get hacked. I'm sure counterpane does a bang up job, but what you're talking about should only take a developer a few months to put together. Then you'd have th
My solution (Score:5, Funny)
By the way, I just got laid off, does anyone need a Sys Admin?
Re:My solution (Score:2)
Bro (Score:4, Informative)
I'd rave more, but bro is watching me and wants me to get back to real work.
Realistically.... (Score:2)
A true DMZ is also a good thing to have, seperated by another firewall, if you have enough infrastructure to justify an (n)tiered network.
Firewalls aren't the end-all-be-all, but They do make compromises much less likely.
As to
Re:Realistically.... (Score:2)
Re:Realistically.... (Score:2)
snort patch (Score:2)
Personalized Login System (Score:3, Interesting)
Please enter todays date (MM/DD/YY):
Please enter your username:
Please enter a valid email address:
Please enter your password:
Just randomize the questions (or have a bunch of questions and randomly ask a few of them) and unless someone is really dedicated to get into your system they're just going to choose another target rather than go after your weird setup.
Re:Personalized Login System (Score:5, Funny)
Even simpler: drop the user straight to a working shell. That way, scripts will wait for the "ogin:" and "assword:" strings indefinitely until the connection times out, and legit users won't even have to enter their logins. As for hackers, they'll see the "~$" prompt, won't believe their eyes, will think it's a clever trap or something, and they'll promply disconnect out of paranoid fear
Re:Personalized Login System (Score:2, Troll)
Re:Personalized Login System (Score:2)
Most networks have a variety of protocols running on them, any of which could be an attack vector or used by an attacker once they've compromized your site.
Think simple (Score:2)
Including a significant delay in any authentication system seriously reduces the effectiveness of bruteforce attacks. The delay is only noticed once by regular users and although it might be a headache for those that forget their passwords, an attacker would have to be very patient.
Another approach is to limit the number of login attempts per connection.
Your example may require its users to remember
The program of choice for all Network Admins is (Score:5, Funny)
Norton Internet Security provides a COMPLETE security solution for your machine by promptly blocking all programs on your machine from having any internet access, AT ALL! Buy it today!
Scissors (Score:2)
IBM Has You Covered (Score:3, Informative)
Re:IBM Has You Covered (Score:2)
Astaro (Score:2)
Size (Score:5, Insightful)
If you're doing 500mbit/sec+ of traffic, it requires a somewhat beefy snort box just to process that data let alone do something about anything that looks like an attack.
Snort CAN do it, it just takes a lot of effort to pair down the ruleset to the point where it can handle your traffic. But, pairing down the ruleset has some drawback
Or, if you can segregate your network, that can help a lot too. But unfortunately, a lot of networks suffer from a lack of design and you end up with huge VLANs that span thousands of hosts, and other nightmares.
IMHO If you're worried about intrusion, start with host security. If you have a huge farm of linux boxes, then great. Use iptables and keep everything up to date. If you MUST have sun boxes, try not to put them on the edge of your network - NAT specific ports via linux NAT firewalls. Same goes for windows machines. Don't bare them to the internet for any reason.
Have some aggressive ACLs on your border routers. Don't allow SSH into all your machines directly. Use jumphosts. Consider using token based authentication, like SecurID. Consider Kerberos to replace the use of public key auth in your ssh infrastructure.
once you have that down, putting in an IDS can wait
Re:Size (Score:2)
Re:Size (Score:2)
Re:Size (Score:2)
/I know, I know
Re:Size (Score:3, Informative)
I recommend Kerberos simply because when you want to disable an account, its as simple as nuking it on the kerberos DC. If you have 200 machines, all with local authentication and RSA keys, you'll have to go through all 200 machines.
Its not ideal, of course. You still need some way of managing user accounts. Bu
I know it's illegal, but (Score:3, Funny)
I reckon if the majority of network admins did that, perhaps intruders would think twice about playing that game. Not to mention the feeling of satisfaction when (if) the intruder's box is trashes in real-time before his eyes
Re:I know it's illegal, but (Score:2, Insightful)
Bad guys would not need zombies anymore for a DDOS: They would simply "attack" a couple of people like you with a forged source address, and let you do the dirty work. Bad Idea[tm] indeed.
Re:I know it's illegal, but (Score:2)
Sorry, I thought we were talking about network intrusion here: surely someone trying to subvert a service (like getting a working shell account, snooping on a Windows box or perusing an intranet) would need a valid IP to do that. Of course, my nasty piece of imaginary software wouldn't fight back DDOSes or spam, since those are essentially impossible to trace back to the original perpetrator.
Re:I know it's illegal, but (Score:3, Insightful)
Sometimes it's not about you.
We're not talking about preventing DDOSs against you; we're talking about provoking your system into initiating a DOS on some other unfortunate victim by poking at your watchdog (junkyard dog?) software with packet probes that have forged source addres
Re:I know it's illegal, but (Score:2)
Re:I know it's illegal, but (Score:2)
Re:I know it's illegal, but (Score:2)
The reason no network admins do what you propose isn't because it's illegal, it's because it's incredibly stupid.
Re:I know it's illegal, but (Score:2)
Re:I know it's illegal, but (Score:2)
Re:I know it's illegal, but (Score:2)
and BTW, it isn't illegal. You are allowed to protect your property, but the problem is collateral damage, which may be illegal.
All you can really do is monitor... (Score:2)
We use... (Score:3, Informative)
Of course, it's needed some tuning so it wouldn' think that things that should be talking to multiple systems in a short time window don't get blocked...
intrusion prevention (Score:5, Interesting)
Companies like Tipping Point have devices that claim to do intrusion prevention with low latency - I'd test that claim before purchase, but the demo I saw seemed to indicate it was worth checking out.
Re:intrusion prevention (Score:2, Informative)
Service is not as good as it used to be, but still decent. They are going through some growing pains and some adjustments after being purchased by 3 Com, but that was to be expected. Their support is still much better than your average vendor.
The rules they use are very conservative, and it affects no other protocols other than IP. It will pass these quite happily, and even the IP tra
Castle gates (Score:3, Interesting)
In order for traffic to get through the outside interface of the inner firewall OR the inside interface of the outer firewall, there needs to be some sort of authentication or other interaction. It need only happen at the start of sessions, but all of
Sentrytools (Score:2)
What more do you need?
The great intrusion prevention debate (Score:3, Informative)
http://www.infoworld.com/article/05/05/09/19FEips
Juniper IDP (Score:3, Informative)
Seriously, though, it's a good system - our sigs are for the most part, open-source - you can see how we detect things, and make a copy and twiddle it yourself. Those few that are closed are generally to protect Intellectual Property concerns.
They're a bit spendy for home use, though. I think the cheapest unit is in the $15-17k range.
Some things also not covered in the question, but imporant issues to raise, are:
1. Ease-of-Use vs. Functionality/Features
2. Performance vs. Security
3. Completeness/Timeliness of Coverage
4. Accuracy
Each IPS vendor has their own angle on these issues, and they're all betting that their angle will be the best - in the end, you as the customer have to decide which of these issues is most important to you, and then find the corresponding vendor.
Juniper has dominant market share, but there are things that other companies do better, but generally at the cost of something we do better at - it's a real mixed bag. See RFC-1925, Section 2, Paragraph 7a for details on this concept.
Juniper IDP is focused on delivering current, feature-rich, accurate detection, generally at the expense of speed and simplicity. Don't get me wrong, though, we're not slugs - our high-end products are currently pushing 2 gig (which in some environments is fast enough). If you want a cheap, 10-gig box with a single "Secure Me" panic button and a single "You Got Owned" idiot light, we're not for you.
Re:Juniper IDP (Score:2)
Would that be Intrusion Detection Prevention?
Where to start? (Score:3, Interesting)
Re:Where to start? (Score:2)
Or do you wait a few days until they've been vetted by the "regulars" and the signature is stable? Well by then you've lost your 'same day sig' advantage.
People who know enough to make their own IPS' from scratch generally already have a clue about netw
Nessus (Score:3, Informative)
As far as "intrusion prevention", there's not a "tool" that does that. You can firewall off unwanted and unneeded traffic; you still need to patch your public services. If you run public services, someone should be responsible for making certain everything you run is up to date and no unpatched vulnerabilities are public (and if the latter is the case, find a workaround or preventative measure until a real patch is out).
Nagios, Mon. et al. (Score:2)
For a network monitor, Nagios (http://www.nagios.org/ [nagios.org] is popular, but I like Mon (http://www.kernel.org/pub/software/admin/mon [kernel.org]), because of its simplicity.
Once you start watching, you realize that you get attacked so much that you quickly scale back the sensitivity. In the end, the monitor becomes a forensics tool, or a way of verifying that it's not an attack that's causing what
Use p0f for logging... (Score:2)
Modern "Firewalls" (Score:5, Informative)
These devices can scan most TCP protocols for any kind of malicious content, like snort-style IPS sigs, viruses, phishing sigs, spyware (generally ActiveX), etc. And since they are the gateway, they can also block or sanitize the content. Some of the better implementations (I'll stop short of a specific product endorsement) can even scan all generic TCP streams, and do not impose any size or stream concurrency limitations on the the content they can scan.
The thing to be careful about is throughput - even the higher end models fall short of sustaining gig throughputs, so multiple devices might be required for more demanding networks.
I've seen a bunch (Score:3, Informative)
I've seen plenty of appliances out there. Some of your options depends on what kind of equipment you're already running. As far as "best choice", you really should factor in what you already have- if you have Cisco modular equipment at your core or distribution layer, maybe going with the Cisco IDS blade will make more sense than getting a Proventia. Do you have Juniper firewalls? They make an IDS blade that fits in their ISG series.
That being said, I've worked with Cisco IDS and SecureAgent. SA's a real beast- you can expect to spend a long time getting up to speed with it. I've had problems managing the blades themselves- they're basically little RedHat boxes on a blad that plugs into the backplane. CiscoWorks makes it relatively easy to manage but I had a *lot* of problems pushing updates and management info to them, and configuring your modular chassis with the right VLAN stuff can be a bitch unless you're good with Cisco equipment. One issue I hope they fixed was that their email notification sucked and they had to provide a PERL script to generate a useful email alert.
I like Juniper's IDP stuff. Their appliances come with cobber and fibre cards and are a snap to set up. You can set them in in pass-through mode and place them inline between your routers and switches, or just mirror/tap the trunk port. In inline mode you get the ablity to send hard RSTs to both endpoints of an attack. The management software is pretty intuitive and the dashboard give you a very good "at a glance" view. They top out at about 500Mbps/sec so if you're pushing great gobs of data, they might not be sufficient.
I've played around a bit with ISS' Proventia stuff- their appliances are OK, and I think their desktop stuff needs one more development cycle to be good. SiteProtector is decent, but it too needs a little more development in the UI area. The desktop agents are a lot easier to manage than Cisco's SecureAgent.
No quick, easy answer (Score:3, Informative)
Clearly, you don't pay much attention to the glossy ads in Infoworld and CIO magazine. FUD marketing out the wazoo for exactly these types of devices.
This is actually a very hard problem to solve. I've written quite a bit on the subject, but I'll attempt to provide a few quick helpful points.
If you have some form of perimeter security, it becomes easier, but still very resource-intensive (both technology resources and human resources). I'm assuming that you're not at a university, or some other type of organization that has a wide open network, because if you were, you wouldn't care.
For a good list of fun tools, look here:. html [stanford.edu]
http://www.slac.stanford.edu/xorg/nmtf/nmtf-tools
But beyond the rinky-dink stuff, at the most basic level, you want to make two choices right up front:
How important is the real-time interdiction to you?
Do you want signature-based tools, anomaly-based tools, or both?
If you would be content with a good system that doesn't have the ability to mitigate threats in real-time, then that widens your possible solution space quite a bit. In this area, you definitely get what you pay for. FOSS tools that have this capability are way behind commercial tools in ease of maintenance, configuration, and how many types of attacks they work against. So that requirement limits your options considerably.
A similar situation exists when we look at the detection method, signature vs. anomaly. Signature-based systems are a dime a dozen, but they don't cover the really dangerous stuff. Anomaly-based systems are somewhat more useful against the scarier threats, but no FOSS solution comes anywhere close to the commercial offerings. If you choose a FOSS alternative for an anomaly-based IDS/IPS, you will spend so much effort tuning and maintaining that you won't have any time left to respond to issues, and you will still not get adequate results.
I should point out that you have also limited yourself by considering only NIDS/IPS systems. The proper bundle of technologies and tools could give you the real intelligence that you need, whether or not it included NIDS/IPS. Other classes of tools, like SIMS, accounting systems, or deception environments have their uses too.
There are plenty of other aspects to consider, but that would take pages to discuss. All of this could be moot depending on your traffic loads, user demographics, platform constituency, infrastructure design, org chart, geographic distribution, existing IT policies, etc. etc. etc. There's just no universal solution.
This is an active area of CS research (Score:3, Informative)
A lot of people are trying to come up with data mining tools for intrusion detection. Just check out all the forward links to this paper from citeseer [psu.edu]. The problem is that they are currently reliable as bad motion detectors ... too many false positives. Which makes them useless.
Re: (Score:2)
Re:commercial products (Score:2)
ISS' stuff... eek. Maybe in a few months after they've gone through another development cycle. I just finished an eval of their stuff and their pre-sales team walked away with
I don't know about you guys (Score:2)
but my network immediately electrocutes the intruder.
Solution Used (Score:2)
Script monitors ports, ips, etc and baselines their activity. If the threshold for activity is exceeded the port,ip is blocked and an email is sent with an unblock link for the admin. Merging an IDS log into a script like that should be straight forward.
Re:Solution Used (Score:3, Informative)
AirSnare (Score:2)
It can be set to email the admin in cases of unauthorized access, and it works in conjunction with Ethereal and AirHorn as well.
Oh, and it's free (as in beer).
Defense In Depth (Score:2, Informative)
To truly protect your system(s), you need to do many different things, including keeping the system updated, educating users, using a NAT, installing an IDS, and much more. That said, an IDS is probably one of the last things you should worry about: get your "basics"
Snort supports in-line operation (Score:4, Informative)
Snort supports in-line (intrusion prevention) operation on Linux as of version 2.3.0. There is also the snort-inline project [sourceforge.net] which maintains a different code branch that includes support for divert sockets on FreeBSD as well as some in-line focused mods.
Sourcefire [sourcefire.com] (my company) builds commercial-grade IPS using Snort as the foundation technology and it works well. We're continuing to improve the technology on an ongoing basis as it's central to our IPS offerings. If you want to run an IPS to try out the technology, Snort is certainly suitable today.
QRadar (Score:2, Informative)
Re:intrusion detection (Score:5, Funny)
BTW nice pr0n collection, your space lego photo series in particular is very kinky.
Re:intrusion detection (Score:3, Interesting)
Re:intrusion detection (Score:3, Informative)
Ok, that's just silly. Only the crudest of hacks would show up under who. There are plenty of ways to spawn processes in an attack that would show up under something like ps or top, and not under who.
Not to mention the fact that manually running who or ps is not an intrusion detection system. You want something that monitors activity and at the very least e-mails a sys admin when something strange is happening.
Wait, why am I bothering to respond to this obvious troll?
Re:What do you use? (Score:2)
Re:Snort-Inline+IPTables+Scripts = Decent IPS (Score:2)
Re:Snort-Inline+IPTables+Scripts = Decent IPS (Score:2)
Re:Snort-Inline+IPTables+Scripts = Decent IPS (Score:3, Informative)
s/IPS/DoS/
Any IDS that automatically affects firewall rules is an incredibly dumb idea. Just don't do it. You're putting control of your firewall rules in the hands of an attacker, which makes a DoS attack trivial. I spent a long time convincing management that we didn't want such a system, despite all the vendors' marketing claims that it was an essential part of modern network security. It
Re:Snort-Inline+IPTables+Scripts = Decent IPS (Score:2, Interesting)
So any attack shown as coming from your upstream provider is going to be passed through, isnt' it?
Of course, that very same rule (don't stop your upstream provider) is valid for whatever other "valuable" connections you may have opened (you don't want your IDS to be fooled into droping connections to your e-commerce database server, do you?).
But then, if any "higher privilege" connection is to be opened, probability is that it
Re:Snort-Inline+IPTables+Scripts = Decent IPS (Score:2)
Re:VMS (Score:2)
It's a great OS, but hard to run on equipment most of us have or can afford. If Itaniums were down around the cost of P4's, it would likely draw much more interest.
Re:How About. (Score:2)
a house? (Score:2)
A house in Montana? A house in Egypt?
C'mon, tell us.. how much do those boxes cost?
Re:a house? (Score:2)
Re:a house? (Score:2)
I get it.
Those are nice boxes. I know a couple people at Juniper/Netscreen (they're right down the street) - they take an active interest in making sure that you're happy with the product.
Re:Abstinence (Score:2)
Re:ISS: Industry Leader in IDS and IPS (Score:2)
Their sales guy was pushing the Proventia M at me, but it doesn't fit in our infrastructure well, and tops out at 1Gbps. That's a fraction of the
Re:Almost Perfect Network Security (Score:2)
Nothing is safer than running a CPU nobody can compile for
Re:big on Linux advocacy, small on windows solutio (Score:2)
Hehhehheh!!! Mod parent funny!
[wiping tears from eyes]