<img height="1" width="1" style="display:none;" alt="" src="https://px.ads.linkedin.com/collect/?pid=2975524&amp;fmt=gif">
BLOG

4SICS Conference Recap on Industrial Control Systems

November 16, 2015

I attended the Swedish industrial cyber security conference 4SICS last month, where I also gave a one-day class on analyzing network traffic. 4SICS is the the leading Industrial Control System (ICS) security conference in Europe, which brings in speakers and attendees from all around the world.

Here's my summary on the conference and the status of where Europe and the world is at for Industrial Control Systems.

I have for several years been encouraging companies that run ICS to continuously capture full content network traffic in their networks. The primary benefit of doing so is to enable forensic analysis of the network traffic in case there has been an intrusion in their networks. This doesn't just apply to hacker attacks, it is also possible to detect and investigate malware infections with help of captured network traffic. Unfortunately, very few companies in the ICS field have deployed sniffers in their control systems, but it seems as if this is about to change. During 4SICS this year several presenters gave talks about success stories where captured network traffic was being used to find intrusions and malware in ICS networks.

"If you know what your traffic looks like these things stick out like a sore thumb"- Chris Sistrunk and Robert Caldwell at 4SICS 2015

Chris Sistrunk and Robert Caldwell delivered a talk titled "Missing the obvious: Network Security Monitoring for ICS," where they mentioned a case where network security was the driver for deploying packet sniffers in a plant. Later on it turned out that IT operations also had a lot to benefit from having access to captured network traffic, since it allowed them to detect misconfigured servers, clients and embedded devices on their networks. Chris and Robert also pointed out that the deterministic nature of ICS network traffic make it easy to find malicious traffic caused by malware.

Rob Caldwell and Chris Sistrunk at 4SICS

Another presenter who used similar tactics was Robert M. Lee, who did a great talk titled, “Asset Identification and Network Security Monitoring in ICS Networks.” In his talk Robert mentioned that he could find malware in ICS networks simply by looking for deviations in the network traffic. Robert also mentioned the problems involved with applying security patches to machines in control systems. Robert said "If you can't patch it, at least monitor it," which is a very sane approach for how to handle situations where critical systems cannot be patched.

The 4SICS conference used an app poll during each talk, which gave some some interesting responses. For example, we could see that 13% answered that they had implemented a solution for network security monitoring in their control systems. So, what's stopping the other 87% of ICS network owners from capturing their network traffic?

Harsh Environments are Just One Concern of ICS Networks

One might argue that the harsh environments that many ICS network run in (water treatment plants, power plants, transformer stations, oil rigs etc.) are not suited for traditional IT appliances designed for climate controlled data centers. However, there is no need to buy an appliance to capture network traffic. All that is needed is a basic linux server running an open source packet sniffer.

For people like me that have high requirements for reliability and minimal packet loss in their capturing setups, a monitor port on a switch is not the preferred method for accessing network traffic. I always prefer a proper network TAP over having a switch with a monitor port.

The industrial Ethernet sector has unique requirements for network access, including 35mm DIN rail support and 24V power connectors, IP ratings for humidity, dust, and other environmental concerns that our indicative of industrial settings.

I’ve been working with Garland Technology on adapting their current line of 10M/100M and 10M/100M/1000M passive TAPs for the function and physicality of industrial networks, which, at the time of this post, is scheduled for release in early 2016.

I'm really looking forward to seeing such a DIN rail mounted network tap in the ICS lab at 4SICS 2016!

35mm Din Rail Mount Network TAP by Garland Technology

To learn more about the differences of network access, read Tim O'Neill's white paper, titled "TAP vs. SPAN". 

 

See Everything. Secure Everything.

Contact us now to secure and optimized your network operations

Heartbeats Packets Inside the Bypass TAP

If the inline security tool goes off-line, the TAP will bypass the tool and automatically keep the link flowing. The Bypass TAP does this by sending heartbeat packets to the inline security tool. As long as the inline security tool is on-line, the heartbeat packets will be returned to the TAP, and the link traffic will continue to flow through the inline security tool.

If the heartbeat packets are not returned to the TAP (indicating that the inline security tool has gone off-line), the TAP will automatically 'bypass' the inline security tool and keep the link traffic flowing. The TAP also removes the heartbeat packets before sending the network traffic back onto the critical link.

While the TAP is in bypass mode, it continues to send heartbeat packets out to the inline security tool so that once the tool is back on-line, it will begin returning the heartbeat packets back to the TAP indicating that the tool is ready to go back to work. The TAP will then direct the network traffic back through the inline security tool along with the heartbeat packets placing the tool back inline.

Some of you may have noticed a flaw in the logic behind this solution!  You say, “What if the TAP should fail because it is also in-line? Then the link will also fail!” The TAP would now be considered a point of failure. That is a good catch – but in our blog on Bypass vs. Failsafe, I explained that if a TAP were to fail or lose power, it must provide failsafe protection to the link it is attached to. So our network TAP will go into Failsafe mode keeping the link flowing.

Glossary

  1. Single point of failure: a risk to an IT network if one part of the system brings down a larger part of the entire system.

  2. Heartbeat packet: a soft detection technology that monitors the health of inline appliances. Read the heartbeat packet blog here.

  3. Critical link: the connection between two or more network devices or appliances that if the connection fails then the network is disrupted.

NETWORK MANAGEMENT | THE 101 SERIES