How to Achieve 20/20 Visibility in Your OT Security

With IT assets comprising 20-50% of modern industrial environments, OT security leaders need technology that can deliver visibility across the converged IT/OT attack surface.

Think back to a recent security incident that impacted the manufacturing or critical infrastructure community. Whether you are thinking of one that was in the news, one that a colleague relayed to you or perhaps one that you may have experienced yourself, you need not look very far. In almost every instance, the affected organization echoes the all-too-common refrain – “I had no idea it was happening until it was too late.”

This is particularly common in operational technology (OT) environments where gear is not swapped out as frequently as in IT environments. The typical approach of “set it and forget it” is common in OT and results in devices that remain in operation for more than a decade. The “forget it” part of this mantra produces a critical visibility problem: it is hard to protect what you do not know you have.

While visibility may be the single most important and obvious competency when it comes to achieving organizational security, its execution has never been quite as trivial. Here are three practices to help gain the visibility you need in order to apply the security and control piece of the puzzle that is needed to avoid attacks. 

• Choose coverage that scales: Ensure that the security you choose can support the environment you administer. Too often, organizations will buy an OT security product or solution only to realize that it does not support the protocols being used or the programmable logic controllers (PLCs) on which their OT operations run. This can easily be addressed by ensuring during a proof of concept (POC) that the vendor has the coverage you need along with a broad range of support from other PLC manufacturers you may consider down the road. This allows the product to grow with your needs rather than locking you into a product that is not forward-compatible.
• Remember that OT is not just OT: In a typical OT environment, 20% of the infrastructure can easily contain IT devices, and this number can quickly rise to 50% in a converged environment. Point OT security products may adequately support OT assets, yet they are completely blind to the IT devices in the OT environment. As seen in recent attacks such as Lockergoga, EKANS and Ripple, which traversed IT and OT, only having partial visibility can introduce a false sense of security and substantial cyber exposure. To achieve the visibility you need, your OT security solution must not only provide you with deep network and OT device intelligence, but also extend beyond OT to IT in order to provide uninterrupted visibility across a converged environment. 
• Apply prioritization to the data deluge: Now that you have the visibility you need, you’ll likely have a lot more data to consume. How should you triage alarms, alerts and investigations? A prioritized risk score is essential to determine which alarms carry the greatest risk to your organization based on type of attack, asset criticality, availability of exploit code and other key factors. This helps focus security personnel on the cyber exposure incidents that present a clear and present risk, while minor or less significant alarms can be addressed later. 

The only way to arrest the proliferation of attacks in critical infrastructure and manufacturing environments is to illuminate the proverbial dark corners of OT environments where security incidents can form. With the right OT security tools, we can gain the visibility we need to no longer fly blind. 

Recently, we released Tenable.ot 3.7 which incorporates the three best practices noted above. We cover more than 90% of industrial controllers on the market today, with more being added each month. We added Nessus into Tenable.ot to address both the IT and OT parts of your industrial operation, providing the domain expertise in both areas that you’ll need to address ALL of your security incidents. We also added our Vulnerability Priority Rating (VPR) to Tenable.ot which can triage incidents based on which vulnerabilities contain the most risk for your organization. 

There is a whole lot more we added to address converging environments and evolving security threats that can put your organization at risk. You can check out our press release for more details about the product update. With the right visibility, security and control in place, you can take advantage of all of the benefits of new technology without being exposed to unacceptable risk.