Thursday, February 08, 2007

IP Tagging

I just read Godfadda's blog entry about a prototype system for tagging IP addresses in Splunk. His system analyzes IP addresses as they're about to be inserted into his log/event tracking system and cross references them with several databases in order to generate additional tags to provide additional context to the event.

Right now, his system deals with geography ("which branch office is this in?") and system role ("Is this an admin's workstation, a server or a public PC?"). I really like this idea, as it provides valuable context when evaluating events.

In fact, I've done a lot of thinking recently about how to add more context to NSM information, but it wasn't until I read this article that I realized that what I was looking for would probably best be implemented as a tagging system. What if Sguil were to incorporate tagging? Well, we'd first have to figure out what to tag. I'd like to be able to tag several types of objects:

  1. IP addresses
  2. Ports
  3. Events
  4. Session records
  5. Packet data for specific flows (probably would treat the pcap file and any generated transcript as a single taggable object)

As for the tags themselves, the system should automatically generate tags based on some criteria, just as in Godfadda's system. Maybe it would automatically tag everything in my exposed web server network as internet,webserver, for example, or maybe it could correlate my own IPs to an asset tracking system to identify their function and/or location.

But here's the part I think would be even more useful: I'd like to have the analyst be able to tag things on-the-fly, and later search on those tags to find related information. For example, if someone has broken into my web server, I could tag the original IDS alert(s) with an incident or case number (e.g., "#287973"). Perhaps this would also automatically tag the attacker's IP with the same number. As I continue to research the incident, I will probably perform SANCP searches, examine the full packet data and generate transcripts. I could tag each of the interesting events with the same ID. At the end of the investigation, I could just do a search for all objects tagged with #287973, order them by date & time, and presto! The technical portion of my report is almost written for me! This is quite similar to other forensic analysis tools (EnCase, for example) that allow you to "bookmark" interesting pieces of information and generate the report from the bookmark list.

To go a bit further, what if the same attacking IP came back six months after the above incident, this time with an FTP buffer overflow exploit? You might not remember the address as the origin of a previous incident, especially if you have a large operation and the original incident was logged by a different analyst. However, if the console says that the address was tagged as being part of a specific incident, you'll know right away to treat it with more suspicion that you might otherwise have done.

To be honest, these are just some of my first ideas on the power of tags; the real power could come as we consider more elaborate scenarios. What if you could tag any item more than once? Well, by associating multiple incident tags with an item, you just might uncover relationships that you didn't realize existed. It doesn't take much to imagine a scenario where you can build a chain of related tags that could imply association between two very different things, perhaps by creating a series of Kevin Bacon links between addresses and or events.

So, will any of this show up in Sguil? Probably not any time soon. Maybe if I can convince Bamm that I'm not insane, maybe it'll find its way onto a feature wish list. Or maybe another project or product will beat us to the punch (it is the era of Web 2.0 after all, and tagging is like breathing to some folks nowdays). But I do fantasize about it, and I live in hope.

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