Tag Archive for: OT

From Reactive to Proactive: Transforming Healthcare Cybersecurity Post-Change Healthcare Attack

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Change Healthcare, a major player in the healthcare technology sector, fell victim to a ransomware attack in February and is quickly heading towards a billion dollars in loss. The breach disrupted its operations and potentially compromised sensitive patient data. The attackers, ALPHV, also known as BlackCat and Noberus, exploited vulnerabilities in the company’s IT infrastructure, likely through phishing emails or other means, to gain unauthorized access to their systems. This breach not only posed a significant threat to patient privacy but also raised concerns about the integrity of healthcare data and the reliability of essential services.

In the landscape of healthcare, where interconnected IT, operational technology (OT), and Internet of Things (IoT) networks are the norm, it’s inhumanly difficult to understand the whole attack surface.  This is why experts and regulators advise adopting a proactive approach to security with best practices including segmentation – keep separate things apart, so that an attacker cannot easily spread from one place to another.  Defenders of healthcare networks need automated assessment of their defensive posture, to uncover gaps and ensure good hygiene ahead of the next attack.

Healthcare administrators must fortify network infrastructure with stringent policies, including robust password enforcement, firewall configurations, and access controls. Vigilant monitoring and configuration of all connected devices, from medical equipment to personal devices, are imperative. Employing strong encryption further enhances data security, deterring cyber intrusions.

Another best practice is implementing a framework such as NIST and MITRE ATT&CK as part of your comprehensive cyberdefense efforts. Take for example another high-growth healthcare organization. Managing 20,000 clinicians and 150,000 medical devices, taking a proactive approach to network visibility and vulnerability prioritization is critical. As cyberattacks have become more sophisticated, healthcare organizations must be proactive and adopt best practices to, as this health system’s cybersecurity expert put it, “prepare the battle space.” In addition to having a dynamic map of their environment, the health system relies on the MITRE ATT&CK (adversarial tactics, techniques, and common knowledge) framework, a comprehensive knowledge base that gives security personnel key insights into attacker behavior and techniques, to help it prevent potential attacks and keep patient information, payment information, and other key data secure.

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Regular attack surface scans are essential for proactive risk mitigation, providing crucial insights for informed decision-making in cybersecurity strategy development. Prioritizing rigorous testing of all software and device updates is crucial to preempt vulnerabilities.

Secure your healthcare network comprehensively with RedSeal. Our network exposure analytics platform offers dynamic visualization of network ecosystems, empowering organizations to identify and address vulnerabilities efficiently. Partnering with leading infrastructure suppliers, we deliver unparalleled network security solutions and professional services, ensuring robust protection against evolving threats.

Reach out to RedSeal or schedule a demo today.

Tales from the Trenches: Network Backdoors — Lions, and Tigers, and Bears…

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Today’s tale from the trench is brought to you by Brad Schwab, Senior Security Solutions Consultant.

One of the greatest concerns for professionals in Network and Security Operations is the potential existence of a backdoor in their network—let alone the presence of numerous backdoors! Identifying backdoors can be a daunting challenge, as they might exist beyond the confines of the configured routing table or take a longer path than the optimized routing path typically followed by traffic. Consequently, conventional traffic mapping tools seldom uncover the presence of a backdoor.

RedSeal is unique in its ability to identify and display all paths through a network, regardless of routing protocols and network address translation (NAT)—therefore exposing all potential backdoors.

While working with a power generation company that managed many extremely remote renewable energy sites, I performed RedSeal data collections on network device configurations across the organization, including company headquarters. From there, I began to perform RedSeal data collections on the power generation farms networks. With this data, I was able to model their network and gain visibility into all the access across their network fabric.

Once all data was collected, we initiated an examination of access vectors into the local generating networks. While engaged in this process, one individual began discussing how the heightened global threat levels had prompted the implementation of a company policy mandating a firewall at each site. This measure aims to safeguard Operational Technology (OT) devices and SCADA Systems. SCADA (Supervisory Control and Data Acquisition) is a software application used for controlling industrial processes by gathering real-time data from remote locations to control equipment and conditions.

As we began verifying that access controls were in place, we concluded there were indeed firewalls present with Access Control Lists (ACLs) blocking and filter inbound traffic. However, because RedSeal shows ALL access vectors, we also noticed that each generation site had two available paths to the internal network—one controlled and limited by the firewall and another that was wide open through the on-site router — a backdoor!

Through RedSeal’s security methodology of “Discover, Investigate, Act” we were able to uncover the backdoors and found that though we started with a small sample of sites, we now knew what to look for and each one had backdoors into the power generation network.

During our investigation we discovered that the secondary wide open access had been set in the case of a site lockout on the firewall. I have seen networks set up like this in the past, although not quite at this scale. It is not terribly uncommon in remote locations to set up a backdoor enabling remote access – however, we learned that with this set up even a firmware upgrade would cause problems. I explained how RedSeal could help verify changes before deployment and then verify implementation with ongoing monitoring for the entire generating network to ensure all sites were always in compliance and no backdoors were in place.  I like to think of it as an always on, always up-to-date audit.  Thus, avoiding any “negative compliance drift” between yearly scheduled audits.

In summary, RedSeal was able to show all the paths through the network—not just the ones that traffic is currently traveling on.  For each path of interest, in this case the backdoors, RedSeal shows every device along the path (hops), and all the ports and protocols that are available for traffic to transit.  Finally, such access can be monitored on an ongoing basis to ensure it does not stray from company policy.

At RedSeal, we’re committed to helping you fortify your digital infrastructure, for good. We proactively help visualize your network, identify attack paths, prioritize risk, and help you stay in compliance to ensure your business and customers stay secure.

Reach out to RedSeal or schedule a demo today.

Expert Insights: Building a World-Class OT Cybersecurity Program

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In an age where manufacturing companies are increasingly reliant on digital technologies and interconnected systems, the importance of robust cybersecurity programs cannot be overstated. While attending Manusec in Chicago this week, RedSeal participated on a panel of cybersecurity experts to discuss the key features, measurement of success, and proactive steps that can lead to a more mature OT (Operational Technology) cybersecurity posture for manufacturing companies. This blog provides insights and recommendations from CISOs and practitioners from Revlon, AdvanSix, Primient, Fortinet, and our own Sean Finn, Senior Global Solution Architect for RedSeal.

Key features of a world-class OT cybersecurity program

The panelists brought decades of experience encompassing a wide range of manufacturing and related vendor experience and the discussion centered around three main themes, all complemented by a set of organizational considerations:

  • Visibility
  • Automation
  • Metrics

Visibility

The importance of having an accurate understanding of the current network environment.

The panel unanimously agreed – visibility, visibility, visibility – is the most critical first step to securing the network. The quality of an organization’s “situational awareness” is a critical element towards both maximizing the availability of OT systems and minimizing the operational frictions related to incident response and change management.

Legacy Element Management Systems may not be designed to provide visibility of all the different things that are on the network. The importance of having a holistic view of their extended OT environment was identified in both proactive and reactive contexts.

The increasingly common direct connectivity between Information Technology (IT) and Operational Technology (OT) environments increases the importance of understanding the full scope of available access – both inbound and outbound.

Automation

Automation and integrations are key components for improving both visibility and operational efficiency.  

  • Proactive assessment and automated detection: Implement proactive assessment measures to detect and prevent segmentation violations, enhancing the overall security posture.
  • Automated validation: Protecting legacy technologies and ensuring control over IT-OT access portals are essential. Automated validation of security segmentation helps in protecting critical systems and data.
  • Leveraging system integration and automation: Continue to invest in system integration and automation to streamline security processes and responses.

Metrics

Measuring and monitoring OT success and the importance of a cybersecurity framework for context. 

One result of the ongoing advancement of technology is that almost anything within an OT environment can be measured.

While there are multiple “cybersecurity frameworks,” the panel was in strong agreement that it is important to leverage a cybersecurity framework to ensure that you have a cohesive view of your environment.  By doing so, organizations will be better-informed regarding cybersecurity investments and resource allocation.

It also helps organizations prioritize and focus on the most critical cybersecurity threats and vulnerabilities.

The National Institute of Standards and Technology (NIST) cybersecurity framework was most commonly identified by practioners in the panel.

Cybersecurity metric audiences and modes 

Different metrics may be different for very different roles. Some metrics are valuable for internal awareness and operational considerations, which are separate from the metrics and “KPIs” that are consumed externally, as part of  “evidencing effectiveness northbound.”

There are also different contexts for measurements and monitoring:

  • Proactive metrics/monitoring: This includes maintaining operational hygiene and continuously assessing the state of proactive analytics systems. Why would a hack want to get in? What is at risk and why does it matter to the organization? 
  • Reactive metrics/monitoring: Incident detection, response, and resolution times are crucial reactive metrics. Organizations should also regularly assess the state of reactive analytics systems. 
  • Reflective analysis: After incidents occur, conducting incident post-mortems, including low-priority incidents, can help identify systemic gaps and process optimization opportunities. This reflective analysis is crucial for learning from past mistakes and improving security. 

 Organizational Considerations 

  1. Cybersecurity risk decisions should be owned by people responsible, and accountable for cybersecurity.
  2. Collaboration with IT: OT and IT can no longer operate in isolation. Building a strong working relationship between these two departments is crucial. Cybersecurity decisions should align with broader business goals, and IT and OT teams must collaborate effectively to ensure security.
  3. Employee training and awareness: Invest in ongoing employee training and awareness programs to ensure that every member of the organization understands their role in maintaining cybersecurity.

Establishing a world-class OT cybersecurity program for manufacturing companies is an evolving process that requires collaboration, automation, proactive measures, and continuous improvement. By focusing on visibility, collaboration, and a commitment to learning from incidents, organizations can build a strong foundation for cybersecurity in an increasingly interconnected world.

Contact RedSeal today to discuss your organizational needs and discover how RedSeal can provide unparalleled visibility into your OT / IT environments.

The Shifting Landscape of Cybersecurity: Top Considerations for CISOs

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1. AI Is Changing the Game

The increasing use of generative AI tools such as ChatGPT comes with both defensive and offensive impacts. On the defensive side, companies can leverage these solutions to analyze security data in real time and provide recommendations for incident response and security vendors developers can write code faster. As for the offensive impact, attackers may be able to optimize malware coding using these same AI tools or leverage code released unknowingly by a security vendor’s developer. If malicious actors can hide compromising code in plain sight, AI solutions may not recognize the potential risk. And if hackers ask generative AI to circumvent network defenses leveraging code released unknowingly, the impact could be significant.

As a result, according to The Wall Street Journal & Forbes, JPMorgan Chase, Amazon, Bank of America, Citigroup, Deutsche Bank, Goldman Sachs and Wells Fargo are limiting employees’ ChatGPT use and we expect to see other companies follow.

2. Market Forces Are Shaping Security and Resilience

The looming economic recession is shaping corporate practices around security and resilience. While many IT teams will see their budgets unchanged or even increased in 2023 compared to 2022, security professionals should also expect greater oversight from C-suite executives, including chief information officers (CIOs), chief information security officers (CISOs), and chief financial officers (CFOs).

Both CIOs and CISOs will expect teams to justify their spending rather than simply giving them a blank slate for purchasing, even if the budget is approved. CFOs, meanwhile, want to ensure that every dollar is accounted for and that security solutions are helping drive business return on investment.

Consider network and cloud mapping solutions that help companies understand what’s on their network, where, and how it’s all connected. From an information security perspective, these tools have value because they limit the frequency and severity of IT incidents. But from a CFO perspective, the value of these tools ties to their ability to save money by avoiding the costs that come with detection, remediation, and the potential reputation fallout that occurs if customer data is compromised and acts as a force multiplier across multiple teams.

3. Multiple Vendor Architecture Is Everywhere

Firewall options from cloud vendors do not meet the enterprise’s security requirement. Enterprises are deploying traditional firewalls (ex. Palo Alto Network, Cisco or Fortinet) in their clouds. They are using cloud workload protection tools from vendors such as Crowdstrike or SentinelOne.

On-premises or cloud deployments cannot be treated in a silo. An adversary could get in from anywhere and go anywhere. The infrastructure has to be treated as one with proper segmentation. Pure-play cloud companies are also switching to on-premises collocated data centers to save on their rising cloud costs.

4. Public Oversight Impacts Private Operations

The recently announced National Cybersecurity Strategy takes aim at current responsibilities and long-term investments. According to the Strategy, there must be a rebalancing of responsibilities to defend cyberspace that shifts away from individuals and small businesses and “onto the organizations that are the most capable and best-positioned to reduce risks for all of us.” The strategy also recommends that businesses balance short- and long-term security investments to provide sustained defense over time.

To help companies achieve these goals, the Cybersecurity and Infrastructure Security Agency (CISA) recently released version 1.0.1 of its cross-sector cybersecurity performance goals (CPGs). Many of these goals fall under the broader concept of “security hygiene,” basic tasks that all companies should complete regularly but that often slip through the cracks.

For example, CPG 2.F recommends that companies use network segmentation to limit the impact of Indicator of Compromise (IOC) events. CPG 1.A, meanwhile, suggests that companies inventory all IT and OT assets in use, tag them with unique identifiers, and update this list monthly.

While no formal announcements have been made, it’s possible that under the new strategy, CISA will shift from providing guidance to enforcing regulatory expectations. For example, FDA may mandate pharmaceutical companies to submit their compliance to CISA CPGs.

5. IT and OT Meet in the Middle

RSA 2023 also touched on the continued merger of IT and OT environments. For many companies, this is a challenging shift. While IT solutions have been navigating the public/private divide for years, many OT frameworks are still not designed to handle this level of connectivity.

The result? A rapidly increasing attack surface that offers new pathways of compromise. Consider an industrial control system (ICS) or supervisory control and data acquisition (SCADA) system that was historically air-gapped but now connects to internal IT tools, which in turn connect to public cloud frameworks. If attackers are able to compromise the perimeter and move laterally across IT environments into OT networks, they will be able to encrypt or exfiltrate customers’ personal and financial data. Given the use of trusted credentials to access these systems, it could be weeks or months before companies notice the issue.

To mitigate the risks, businesses are looking for ways to segment IT and OT plus continuously validate segmentation policies are met. This starts with the discovery and classification of OT devices along with the development of standards-based security policies for both IT and OT functions. These two networks serve different aims and need to avoid the risk of any lateral movement between the networks.

Old, New, and Everything in Between

OT threats are on the horizon, companies need to prioritize basic security hygiene, and economic downturns are impacting IT budgets. These familiar frustrations, however, are met by the evolution of AI tools and the development of new national strategies to combat emerging cyber threats. As we look towards the second half of the year, the lessons learned can help companies better protect what they have and prepare for the next generation of cybersecurity threats. Take on the new cybersecurity landscape with RedSeal. Reach out to see how we can help you. 
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Purdue 2.0: Exploring a New Model for IT/OT Management

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Developed in 1992 by Theodore J. Williams and the Purdue University Consortium, the Purdue diagram — itself a part of the Purdue Enterprise Reference Architecture (PERA) — was one of the first models used to map data flows in computer-integrated manufacturing (CIM).

By defining six layers that contain both information technology (IT) and operational (OT) technology, along with a demilitarized zone (DMZ) separating them, the Purdue diagram made it easier for companies to understand the relationship between IT and OT technologies and establish effective access controls to limit total risk.

As OT technologies have evolved to include network-enabled functions and outward-facing connections, however, it’s time for companies to prioritize a Purdue update that puts security front and center.

The Problem with Purdue 1.0

A recent Forbes piece put it simply: “The Purdue model is dead. Long live, Purdue.”

This paradox is plausible, thanks to the ongoing applicability of Purdue models. Even if they don’t quite match the reality of IT and OT deployments, they provide a reliable point of reference for both IT and OT teams.

The problem with Purdue 1.0 stems from its approach to OT as devices that have MAC addresses but no IP addresses. Consider programmable logic controllers (PLCs). These PLCs typically appear on MAC addresses in Layer 2 of a Purdue diagram. This need for comprehensive visibility across OT and IT networks, however, has led to increased IP address assignment across PLCs, in turn making them network endpoints rather than discrete devices.

There’s also an ongoing disconnect between IT and OT approaches. Where IT teams have spent years looking for ways to bolster both internal and external network security, traditional OT engineers often see security as an IT-only problem. The result is IP address assignment to devices but no follow-up on who can access the devices and for what purpose. In practice, this limits OT infrastructure visibility while creating increased risk and security concerns, especially as companies are transitioning more OT management and monitoring to the cloud.

Adopting a New Approach to Purdue

As noted above, the Purdue diagram isn’t dead, but it does need an update. Standards such as ISA/IEC 62443 offer a solid starting point for computer-integrated manufacturing frameworks, with a risk-based approach that assumes any device can pose a critical security risk and that all classes of devices across all levels must be both monitored and protected. Finally, it takes the position that communication between devices and across layers is necessary for companies to ensure CIM performance.

This requires a new approach to the Purdue model that removes the distinction between IT and OT devices. Instead of viewing these devices as separate entities on a larger network, companies need to recognize that the addition of IP addresses in Layer 2 and even Layer 1 devices creates a situation where all devices are equally capable of creating network compromise or operational disruption.

In practice, the first step of Purdue 2.0 is complete network mapping and inventory. This means discovering all devices across all layers, whether they have a MAC address, IP address, or both. This is especially critical for OT devices because, unlike their IT counterparts, they rarely change. In some companies, ICS and SCADA systems have been in place for 5, 10, even 20 years or more, while IT devices are regularly replaced. As a result, once OT inventory is completed, minimal change is necessary. Without this inventory, however, businesses are flying blind.

Inventory assessment also offers the benefit of in-depth metric monitoring and management. By understanding how OT devices are performing and how this integrates into IT efforts, companies can streamline current processes to improve overall efficiency.

Purdue Diagram

 

Controlling for Potential Compromise

The core concept of evolving IT/OT systems is interconnectivity. Gone are the days of Level 1 and  2 devices capable only of internal interactions, while those on Levels 3, 4, and 5 connect with networks at large. Bolstered by the adoption of the Industrial Internet of Things (IIoT), continuous connectivity is par for the course.

The challenge? More devices create an expanding attack surface. If attackers can compromise databases or applications, they may be able to move vertically down network levels to attack connected OT devices. Even more worrisome is the fact that since these OT devices have historically been one step removed from internet-facing networks, businesses may not have the tools, technology, or manpower necessary to detect potential vulnerabilities that could pave the way for attacks.

It’s worth noting that these OT vulnerabilities aren’t new — they’ve always existed but were often ignored under the pretense of isolation. Given the lack of outside-facing network access, they often posed minimal risk, but as IIoT becomes standard practice, these vulnerabilities pose very real threats.

And these threats can have far-reaching consequences. Consider two cases: One IT attack and one OT compromise. If IT systems are down, staff can be sent home or assigned other tasks while problems are identified and issues are remediated, but production remains on pace. If OT systems fail, meanwhile, manufacturing operations come to standstill. Lacking visibility into OT inventories makes it more difficult for teams to both discover where compromise occurred and determine the best way to remediate the issue.

As a result, controlling for compromise is the second step of Purdue 2.0. RedSeal makes it possible to see what you’re missing. By pulling in data from hundreds of connected tools and sensors and then importing this data into scan engines — such as Tenable — RedSeal can both identify vulnerabilities and provide context for these weak points. Equipped with data about devices themselves, including manufacturing and vendor information, along with metrics that reflect current performance and behavior, companies are better able to discover vulnerabilities and close critical gaps before attackers can exploit OT operations.

Put simply? Companies can’t defend what they can’t see. This means that while the Purdue diagram remains a critical component of CIM success, after 30 years in business, it needs an update. RedSeal can help companies bring OT functions in line with IT frameworks by discovering all devices on the network, pinpointing potential vulnerabilities, and identifying ways to improve OT security.

InfoSeCon Roundup: OT Top of Mind with Many

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The RedSeal team recently attended the sold-out ISSA Triangle InfoSeCon in Raleigh. It was energizing to see and talk to so many people in person. People were excited to be at in-person events again (as were we!) and we had some great discussions at our booth on how RedSeal can help customers understand their environment and stay one step ahead of threat actors looking to exploit existing vulnerabilities. 

Visibility was a top topic at the booth, but I want to focus this blog on our panel discussion, titled ”OT: Still a Security Blindspot”, which, of course, has visibility as a core need. While I was expecting that this topic would be of interest to quite a few attendees, I was not expecting the great reception we received, nor the number of people that stayed behind to talk to us. We had so many great questions, that we have decided to host a webinar with the same title, where we will share some of the same information, and expand it to address some additional topics based on attendee interest. 

I want to highlight some key points we shared during the session:

We started the session talking about OT networks – what they are, and how they exist across all verticals in some way, shape or form (it is not just manufacturers!).  We did share a life sciences customer example to close the session (think about all of the devices in a hospital connected to the Internet – and what could happen if they were hacked!).

Then we got into the “risk” part of the discussion. We shared how OT networks are targeted via vulnerable devices and highlighted actual consequences from some real-life examples. We focused on the Mirai botnet and potential motives from threat actors:  

  • Botnets can simply to be annoying or attention getting, interrupting business 
  • Ransomware has traditionally been for cash or equivalent, but now can also be for deliberate intentional damage
  • Nation State – with espionage as a goal – to disrupt or compromise organizations or governments

Our panelists from Medigate by Claroty provided their perspective based on discussions with their customers. They explained that for many organizations OT was an afterthought when accessing security risks. The audience appeared to agree with this assessment. Unfortunately, this meant that OT has often been the quickest way to cause serious damage at an organization. They have seen this within the 1500+ hospitals they work with. They shared a couple of examples, which clearly demonstrated what can happen if you have vulnerable OT devices:

  • Turning off the air conditioning at a hospital in Phoenix AZ during the summer shut EVERYTHING down
  • Operating rooms must be kept at very specific temps and humidity levels. A customer in CA whose dedicated O.R. HVAC was impacted ended up losing $1M in revenue PER DAY while it was down

One of the reasons that the security risks for OT devices has not been addressed as well as they should is that OT devices have typically been managed by the Facilities organizations, who do not have the training and expertise needed for this task. We did spend some time talking about who “owns” managing and securing these OT devices. Luckily, there is growing awareness of the need for visibility into both OT and IT devices as part of an overall security strategy, and there are emerging solutions to address this need. 

We also spent time discussing how complex managing OT/IT becomes when companies have distributed sites or complex supply chains. The Medigate panelists shared how some of their Life Sciences customers have sites with different OT network topologies, and some even have a mismatch between the topology of the individual site and its production logic. This means there are usually multiple redundant, unmonitored connections at each site, which provides threat actors with numerous opportunities to penetrate the OT network and, once inside, to move laterally within it. 

This led to a conversation among the panelist on how to address the IT/OT visibility needs:

  1. First step: gain visibility into where OT is and then integrate it with existing IT security infrastructure 
  2. Ongoing: alignment and collaboration between and across IT and OT security, as well as with a range of third-party vendors, technicians, and contractors
  3. End goal: enable all teams (facilities, IT, security, networking, etc.) speak the same language from the same source of truth

The above is just a brief review of some of the topics covered during the panel discussion. If you are interested in hearing more about how to address IT/OT visibility needs and hear about how customers are addressing these needs or find out more about RedSeal, please visit our website or contact us today!

IT/OT Convergence

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Operational Technology (OT) systems have decades of planning and experience to combat threats like natural disasters – forces of nature that can overwhelm the under-prepared, but which can be countered in advance using well thought out contingency plans. Converging IT with OT brings great efficiencies, but it also sets up a collision between the OT world and the ever-changing threats that are commonplace in the world of Information Technology. 

A Changing Threat Landscape 

The security, reliability, and integrity of the OT systems face a very different kind of threat now – not necessarily more devastating than, say, a flood along the Mississippi, or a hurricane along the coast – but more intelligent and malicious. Bad actors connected over IT infrastructure can start with moves like disabling your backup systems – something a natural disaster wouldn’t set out to do. Bad actors are not more powerful than Mother Nature, but they certainly are more cunning, and constantly create new attack techniques to get around all carefully planned defenses. This is why the traditional strategies have to change; the threat model is different, and the definition of what makes a system “reliable” has changed. 

In the OT world, you used to get the highest reliability using the oldest, most mature equipment that could stay the same, year after year, decade after decade. In the IT world, this is the worst possible situation – out of date electronics are the easiest targets to attack, with the most known vulnerabilities accumulated over time. In the IT world of the device where you are reading this, we have built up an impressive and agile security stack in response to these rapidly evolving threats, but it all depends on being able to install and patch whatever software changes we need as new Tactics, Techniques and Procedures (TTP’s) are invented. That is, in the IT world, rapid change and flexible software is essential to the security paradigm. 

Does this security paradigm translate well to the OT world?

Not really. It creates a perfect storm for those concerned with defending manufacturing, energy, chemical and related OT infrastructure. On the one hand, the OT machinery is built for stability and cannot deliver the “five nines” reliability it was designed for if components are constantly being changed. On the other hand, we have IT threats which can now reach into OT fabric as all the networks blend, but our defense mechanisms against such threats require exactly this rapid pace of updating to block the latest TTP’s! It’s a Catch-22 situation. 

The old answer to this was the air gap – keep OT networks away from IT, and you can evade much of the problem. (Stuxnet showed even this isn’t perfect protection – humans can still propagate a threat across an air gap if you trick them, and it turns out that this isn’t all that hard to do.) Today, the air gap is gone, due to the great economic efficiencies that come from adding modern digital communication pathways to everything we might need to manage remotely – the Internet of Things (IoT).

How do we solve this Catch-22 situation?

So, what can replace the old air gap? In a word, segmentation – it’s possible, even in complex, blended, IT/OT networks to keep data pathways separate, just as it’s essential for the same reason that we keep water pipes and sewer pipes separate when we build houses. The goal is to separate vulnerable and critical OT systems so that they can talk to each other and be managed remotely, but to open only these pathways, and not fall back to “open everything so that we can get the critical traffic through”. Thankfully, this goal is achievable, but the bad news is it’s error prone. Human operators are not good at maintaining complex firewall rules. When mistakes inevitably happen, they fall into two groups:

  1. errors that block something that is needed
  2. errors that leave something open

The first kind of error is immediately noticed, but sadly, the second kind is silent, and, unless you are doing something to automatically detect these errors and gaps, they will accumulate, making your critical OT fabric more and more fragile over time. 

One way to combat this problem is to have a second set of humans – the auditors – review the segmentation regularly. Experience shows, though, that this just propagates the problem – no human beings are good at understanding network interactions and reasoning about complex systems. This is, however, a great job for computers – given stated goals, computers can check all the interactions and complex rules in a converged, multi-vendor, multi-language infrastructure, and make sure only intended communication is allowed, no more and no less.

In summary, IT/OT convergence is inevitable, given the economic benefits, but it creates an ugly Catch-22 scenario for those responsible for security and reliability – it’s not possible to be both super-stable and agile at the same time. The answer is network segmentation, not the old air gapped approach. The trouble with segmentation is it’s hard for humans to manage, maintain and audit without gaps creeping in. Finally, the solution to resolve this Catch-22 is to apply automation – using software such as from RedSeal to automatically verify your segmentation and prevent the inevitable drift, so that OT networks are as prepared for a hacker assault as they are for a natural disaster.