Big Data Security Part One: Introducing PacketPig
Packetloop CTO Michael Baker (@cloudjunky) made a big splash when he presented ‘Finding Needles in Haystacks (the Size of Countries)‘ at Blackhat Europe earlier this year. The paper outlines a toolkit based on Apache Pig, Packetpig @packetpig (available on github), for doing network security monitoring and intrusion detection analysis on full packet captures using Hadoop.
In this series of posts, we’re going to introduce Big Data Security and explore using Packetpig on real full packet captures to understand and analyze networks. In this post, Michael will introduce big data security in the form of full data capture, Packetpig and Packetloop.
Intrusion detection is the analysis of network traffic to detect intruders on your network. Most intrusion detection systems (IDS) look for signatures of known attacks and identify them in real-time. Packetpig is different. Packetpig analyzes full packet captures – that is, logs of every single packet sent across your network – after the fact. In contrast to existing IDS systems, this means that using Hadoop on full packet captures, Packetpig can detect ‘zero day’ or unknown exploits on historical data as new exploits are discovered. Which is to say that Packetpig can determine whether intruders are already in your network, for how long, and what they’ve stolen or abused.
Packetpig is a Network Security Monitoring (NSM) Toolset where the ‘Big Data’ is full packet captures. Like a Tivo for your network, through its integration with Snort, p0f and custom java loaders, Packetpig does deep packet inspection, file extraction, feature extraction, operating system detection, and other deep network analysis. Packetpig’s analysis of full packet captures focuses on providing as much context as possible to the analyst. Context they have never had before. This is a ‘Big Data’ opportunity.
Full Packet Capture: A Big Data Opportunity
What makes full packet capture possible is cheap storage – the driving factor behind ‘big data.’ A standard 100Mbps internet connection can be cheaply logged for months with a 3TB disk. Apache Hadoop is optimized around cheap storage and data locality: putting spindles next to processor cores. And so what better way to analyze full packet captures than with Apache Pig – a dataflow scripting interface on top of Hadoop.
In the enterprise today, there is no single location or system to provide a comprehensive view of a network in terms of threats, sessions, protocols and files. This information is generally distributed across domain-specific systems such as IDS Correlation Engines and data stores, Netflow repositories, Bandwidth optimisation systems or Data Loss Prevention tools. Security Information and Event Monitoring systems offer to consolidate this information but they operate on logs – a digest or snippet of the original information. They don’t provide full fidelity information that can be queried using the exact copy of the original incident.
Packet captures are a standard binary format for storing network data. They are cheap to perform and the data can be stored in the cloud or on low-cost disk in the Enterprise network. The length of retention can be based on the amount of data flowing through the network each day and the window of time you want to be able to peer into the past.
Pig, Packetpig and Open Source Tools
In developing Packetpig, Packetloop wanted to provide free tools for the analysis network packet captures that spanned weeks, months or even years. The simple questions of capture and storage of network data had been solved but no one had addressed the fundamental problem of analysis. Packetpig utilizes the Hadoop stack for analysis, which solves this problem.
For us, wrapping Snort and p0f was a bit of a homage to how much security professionals value and rely on open source tools. We felt that if we didn’t offer an open source way of analysing full packet captures we had missed a real opportunity to pioneer in this area. We wanted it to be simple, turn key and easy for people to take our work and expand on it. This is why Apache Pig was selected for the project.
Understanding your Network
One of the first data sets we were given to analyse was a 3TB data set from a customer. It was every packet in and out of their 100Mbps internet connection for 6 weeks. It contained approximately 500,000 attacks. Making sense of this volume of information is incredibly difficult with current tooling. Even Network Security Monitoring (NSM) tools have difficult with this size of data. However it’s not just size and scale. No existing toolset allowed you to provide the same level of context. Packetpig allows you to join together information related to threats, sessions, protocols (deep packet inspection) and files as well as Geolocation and Operating system detection information.
We are currently logging all packets for a website for six months. This data set is currently around 0.6TB and because all the packet captures are stored in S3 we can quickly scan through the dataset. More importantly, we can run a job every nightly or every 15 minutes to correlate attack information with other data from Packetpig to provide an ultimate amount of context related to security events.
Items of interest include:
- Detecting anomalies and intrusion signatures
- Learn timeframe and identity of attacker
- Triage incidents
- “Show me packet captures I’ve never seen before.”
“Never before seen” is a powerful filter and isn’t limited to attack information. First introduced by Marcus Ranum, “never before seen” can be used to rule out normal network behaviour and only show sources, attacks, and traffic flows that are truly anomalous. For example, think in terms of the outbound communications from a Web Server. What attacks, clients and outbound communications are new or have never been seen before? In an instant you get an understanding that you don’t need to look for the normal, you are straight away looking for the abnormal or signs of misuse.
Packetloop uses the stack and iterative prototyping techniques outlined in the forthcoming book by Hortonworks’ own Russell Jurney, Agile Data (O’Reilly, March 2013). We use Hadoop, Pig, Mongo and Cassandra to explore datasets and help us encode important information into d3 visualisations. Currently we use all of these tools to aid in our research before we add functionality to Packetloop. These prototypes become the palette our product is built from.