Snort mailing list archives
Re: Snort Anomaly
From: Doug Burks <doug.burks () gmail com>
Date: Thu, 9 Jan 2014 07:21:24 -0500
Hi Mr Smith, Kevin provided some great recommendations and you can have many of them up and running in about 15 minutes with Security Onion: http://www.securityonion.net/ Security Onion gives you the following: - Snort and Bro (with PF_RING) - ELSA - Full packet capture - OSSEC HIDS (and much more!) We released an update yesterday that especially helps in finding the anomalies in your network: http://blog.securityonion.net/2014/01/new-securityonion-web-page-package.html Hope that helps! On Wed, Jan 8, 2014 at 11:00 AM, Kevin Ross <kevross33 () googlemail com> wrote:
It depends what you mean by anomaly. These days "anomaly" to me means odd HTTP communications, useragents, geolocation patterns, traffic anomalies like bad fields for DNS or hosts talking on protocols they shouldn't be like non-DNS servers trying to contact external DNS etc. To be more capable of detecting these things and other anomalies I suggest taking a network security monitoring approach with multiple levels of tools. This means collecting various data from IDS, network etc and applying detection to it. An excellent recently released book on this is this which while I am not too far into it the book is truly excellent; especially as it covers snort, anomaly detection, BRO (which very nicely complements things like Snort). http://www.amazon.co.uk/Applied-Network-Security-Monitoring-Collection/dp/0124172083/ref=sr_1_1?ie=UTF8&qid=1389194990&sr=8-1&keywords=applied+network+security+monitoring Obviously though you don't need a book to learn this as you can read documentation on each of these bits. To get to a good detection level I would suggest looking into the following things: - Make sure you have Snort tuned so you aren't overwhelmed and the rules and preprocessors are setup as you want them. Read the Snort documentation on this, a lot of rules and preprocessor settings will highlight traffic anomalies anyway. - Install BRO http://www.bro.org/. It can detect other anomalies and also generates very detailed logs on HTTP traffic, file hashes, tunnels, DNS, other protocols that will complement any alerts you get from Snort etc. I then feed those logs and IDS logs and things into ELSA http://code.google.com/p/enterprise-log-search-and-archive/ which allows me to do querying on all events surrounding a snort alert and also a lot of hunting (i.e show me all unique useragents in my traffic and it will count them up and display that, show me all executables from certain countries etc). With snort I also have Snorby setup and full packet capture with openfpc so it can be queried easily from Snorby from alerts. It can also extract files from the network (which Snort 2.9.6 can do too) but the advantage is also hashing of all files in protocols. So executables, HTML pages, Java files, PDFs everything is getting hashed so even if you don't have a file you can search for the hashes on things like Virustotal. - Setup full packet capture solution like OpenFPC, Moloch or StreamDB (I use OpenFPC due to it being integrated into Snorby and it is less intense than say Moloch which indexes network traffic for my sensors). This allows you to analyse the traffic in depth depending how far you can go back (1 day min 3 days ideal but you may find it is only hours. Still some FPC for as long as your disk space allows (and you can ignore hosts, protocols etc with BPF filters to increase that time) is better than none. - Other types of anomaly detection can be implemented in other things such as if you have a SIEM with your firewall logs going into it if you create a correlation rule for high port numbers (above 1024 but not well known high port numbers like SIP ports etc) and then log for UDP and TCP firewall denies for so many in a certain time like a minute period you will actually pick out P2P protocols with no knowedge of the protocol itself. I.e Using this logic and some negation for my enviroment I reliably have detected (although it may not have been the only alert) BitTorrent Traffic, Zeus trojan P2P protocol and other protocols for malware etc. This will be very useful as P2P is used increasingly in malware families. - Another good thing is PassiveDNS ideas which you can get going with https://github.com/gamelinux/passivedns. Just logging in with NXDOMAINs into a database with the web interface is good and for instance you can create a lookup in Snorby so that when you have an IDS alert you can quickly lookup the IP in your PassiveDNS database for domains which can very quickly help you determine a false positive or a true positive and even when the incident first appeared. I.e I have had alerts for exploit kits but through DNS for the other names resolved to the IP I have found previously used domains and when they were seen and am then able to look back and other logs at those times. Also using regular expressions, blacklists and other methods in SIEM for NXDOMAINs for instance I can detect malicious or suspect domains: i.e alerts for domain generation algorithm domains (https://blog.damballa.com/archives/1504), bad domains, supect domains such as each day I extract with a script all new domains queried (and also cases where new IPs mapped to a name) that day and then with some negation and other things. The logic being if that is the first time ever it has appeared within your enterprise and it looks kind of suspicious it just might be. While no one thing here is a silver bullet the combination of all the combined tools and methods is basically provided lots of ability to detect intrusions, properly analyse them, hunt for the unknown, detect anomalies etc. With this you will end up with: - Snort alerting you to all kinds of intrusions and anomalies. For anomalies though protocol rules and the preprocessors which you can read about in the documentation is where you should look. - BRO IDS providing detailed logging and if fed into something like ELSA, SPLUNK, Logstash etc analytics. Also actual on disk BRO logs compress to very little space automatically so essentially you have a historical record of all flows, IRC chats, FTP traffic, HTTP records, file hashes and so on for a long time of perhaps many months or even years. - Full packet capture. Useful for short term but high detail analysis - File extraction for analysis if you implement in BRO/Snort. You can then do other analysis like running tools on them, checking the file hashes on Virustotal frmo BRO etc - PassiveDNS will allow you to analyse URLs and IPs for their relationships and it will provide a long term historical analysis (i.e a partner organsiation says they have malware which talks to badguys.com. Have you been hit? You can go to that, type it in and if you get results you will have a first and last time to begin hunting through other logs and BRO would have even more detail. Also with regex you can detect all kind of anomalies and if you look at research like http://labs.umbrella.com/ http://www.lastline.com/papers/dns.pdf and https://www.damballa.com/damballa-labs/publications.php you might get more ideas on things in DNS to look for to detect malicious activity (or simply feeding in blacklists of known bad ones). Hope that helps, Kevin On 7 January 2014 18:38, Mr Smith <engineer.demo2020 () gmail com> wrote:Hi I Have a question about Snort: What is the best solution to improve Snort performance in terms of "Anomaly Detection" Capability? What is the best solution to add "Anomaly Detection" capability into Snort? 1. Using a Host-Based IDS(like what?) in conjunction with Snort(NIDS)? 2. Adding anomaly based plugins(like what) into Snort? 3....? Thanks ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ 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://sourceforge.net/mailarchive/forum.php?forum_name=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ 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://sourceforge.net/mailarchive/forum.php?forum_name=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
-- Doug Burks ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ 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://sourceforge.net/mailarchive/forum.php?forum_name=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
Current thread:
- Snort Anomaly Mr Smith (Jan 08)
- Fwd: Snort Anomaly Mr Smith (Jan 08)
- Re: Snort Anomaly Kevin Ross (Jan 08)
- Re: Snort Anomaly Doug Burks (Jan 09)
- Re: Snort Anomaly Kevin Ross (Jan 10)
- Re: Snort Anomaly Kevin Ross (Jan 10)
- Re: Snort Anomaly Doug Burks (Jan 09)