OT Incident Response: 4 Reasons Asset Inventory Is Key

Without a detailed view of the assets and vulnerabilities across your OT environment, security leaders face increased costs and delays when it comes to incident response efforts.

Last week on Twitter there were several discussions centered around recent supply chain attacks as well as the feasibility of scanning for vulnerable devices within operational technology (OT) environments.

A number of incident responders who I respect in the community noted that the first step in any response effort is to gain a full understanding of the environment. Attempting to figure out the full extent of a breach without knowing all the devices connected to your networks and how they are segregated is much like trying to get to a destination without a map or GPS. These professionals will tell you that the lack of an upfront, up-to-date asset inventory significantly increases the cost of incident response efforts.

I often get questions from current and potential customers who are trying to understand whether they should invest in asset inventory, device management and visibility solutions, or in threat hunting and incident response solutions. Quite frankly, over the long-term, the answer is both. But if the organization does not yet have a system of record in place to fully understand the state of all of their assets, and specifically where these devices are vulnerable, then it is clear which one should be the first investment.

Today’s CISOs need continuous visibility

When the board of directors asks whether your organization has been impacted by a recent supply chain attack such as SolarWinds, no chief information security officer (CISO) ever wants to answer “I don’t know.” As the threat landscape continues to evolve at a rapid pace, answering these questions is easier said than done. Hiring a consultant to come in once a year to scan your environment and catalog your devices is no longer sufficient for what would be considered “due diligence.” Organizations must pivot to using continuous, real-time solutions to monitor the myriad of devices that come and go every day on our converged IT – OT networks.

Purpose-built tools uncover all your OT devices

Another valid concern in the OT environment is the utilization of IT-centric scanning tools. It is well-known that such tools used carelessly in these systems can lead to failures and/or process downtime by well-meaning IT security teams. Fortunately, in recent years, purpose-built asset discovery tools have been created specifically for these sensitive OT environments.

Tenable.ot is such a tool. Our active querying technology communicates with sensitive OT controllers and devices utilizing their own native protocols, in exactly the same way that the vendors themselves communicate with the devices during routine system operations. This technology provides a safe, reliable method to simply ask the device about its specific configuration parameters, firmware versions and other relevant metadata. This allows us to gain far more accurate and detailed information about the OT environment than can be inferred through passive network monitoring alone.

Adaptive assessment targets IT devices in OT environments 

It is also well known that OT environments are not simply composed of programmable logic controllers or other similar devices. These environments increasingly incorporate commercial off-the-shelf (COTS) components such as servers running contemporary operating systems like Microsoft Windows. Tenable has long been considered the industry standard when it comes to vulnerability management on such platforms. We have taken the power of Nessus and incorporated it into the Tenable.ot product line, giving you the best of both worlds. You can communicate with sensitive OT devices using their safe and reliable protocols, while also safely scanning the IT systems present in your OT environment with a specialized version of Nessus.

Comprehensive dashboards prioritize remediation actions

Of course, supply chain attacks do not care or limit themselves to one side of the firewall. If you are the CISO, you need to be able to assess the potential impact for both your enterprise and your OT deployments. This is why from day one Tenable.ot communicates these details about your OT environment up into Tenable’s risk-based vulnerability management (RBVM) solution, allowing you to visualize and prioritize — using our Vulnerability Prioritization Rating (VPR) — which systems and devices you need to mitigate first.

Preparing for an incident requires more than putting down a retainer with an incident response company. It means investing upfront in the systems that will give you the ground truth when it comes to information about the state of your assets and where you are most vulnerable.

To learn more, visit our Tenable.ot solution page for additional whitepapers, videos and case studies that show how organizations can increase visibility and reduce risk across their industrial environments.