Fortifying Your Operation: Proven Strategies for Robust OT Network Security in Industrial Environments
In today’s increasingly interconnected industrial landscape, safeguarding your operation’s critical assets is paramount. This article, tailored for plant managers and engineers by a seasoned system integrator, reveals essential insights and strategies to fortify your OT network security, ensuring uninterrupted productivity and protection against cyber threats.
Within the realm of operational technology (OT) lies an intricate web of real-time communication protocols, where the slightest network hiccup can send shockwaves through the production chain, bringing it to a grinding halt. As industries increasingly embrace interconnectedness and automation, the question of how to fortify these vital networks against threats looms larger than ever. In the world of OT network security, the stakes are high, the challenges complex, and the need for vigilance is paramount.
In this article, we will discuss network security, explore the unique vulnerabilities that OT systems face, the evolving threat landscape, and the strategies and technologies that hold the key to safeguarding the lifeline of modern industry. Here, precision is not optional, uptime is the ultimate currency, and security equals risk reduction.
What is OT (Operational Technology)?
OT encompasses all the physical communication technology that runs a manufacturing production line. Some basic examples include PLCs (programmable logic controllers), SCADA (supervisory control and data acquisition) systems, and HMIs (human-machine interfaces). Older equipment is typically stand-alone, whereas newer equipment tends to have network connectivity capability. With network connectivity, there comes both advantages and conveniences, but also security risks.
An OT Failure Can Bring a Line Down
Because OT includes all the equipment that runs a manufacturing process when something fails, it typically brings the line down, and production stops. Depending on the nature of the failure, the result can be devastating. Modern equipment has the ability to connect to an OT network, providing a powerful means for data transfer into, and out of the system. However, the stakes are high. The network must be properly secured to safeguard the manufacturing process.
The Fundamentals of OT Security
Regardless of connectivity, OT security should be considered on the following different levels:
Firewall Protection from Outside Threats
An OT network should be protected from the outside using a firewall, or complete isolation – called air gapping. Should there be a requirement, more options exist to protect your network. Individual computers can have software firewalls installed. Allen Bradley PLCs have several security features, including the ability to restrict which computers can change their code. Most PLCs include a physical switch that can be either in the “Program” or “Run” state. These options allow for stronger security but come with their own downsides. What if the password is lost, or the computer that has code change permission fails? In general, the stronger the security risk, the more features should be considered in the solution, being mindful that having more features means more tradeoffs.
In the event of a security breach, having up-to-date backups of all programs dramatically reduces downtime. It is the fastest path back to production.
Password protection of all touchscreen devices ensures that only those who know how to operate the equipment with which they are associated can do so, avoiding unnecessary tampering.
Lock it Up! (Physical Security)
Be sure to lock up all assets when not in use, so that nobody can physically get to them.
The Unique Considerations of OT Networks Compared to IT Counterparts
OT networks often feature a mix of aging and modern equipment with many lacking the robust security measures found in typical information technology (IT) systems. Because it connects manufacturing equipment, it must communicate at high speed, in a highly coordinated, predictable, and repeatable fashion. OT networks employ static device addressing. This type of addressing is different from IT networks that use dynamic addressing, usually from a domain server. In addition, OT networks are typically implemented in very electronically noisy environments. The cabling that connects equipment must be isolated from noise interference produced by variable frequency drives (VFDs), transformers, and other control systems.
As a result, safeguarding an OT network demands a strategy that looks at the network as a cohesive unit as opposed to focusing on individual components. In this context, instead of trying to protect each machine one by one, it is more economical to focus on defending the entire network from outside threats.
OT Network Security Reduces the Risk of Connectivity
A connected OT Network offers many advantages, including access to remote access, enterprise resource planning (ERP) software, and production monitoring. When security is carefully implemented, the risks of attack can be minimized, while leveraging the associated benefits.
OT Network Risks
When it comes to OT network security, the level of risk primarily depends on how much technology is connected and exposed to the outside world, as this is the predominant source of malicious security breaches. Outside world exposure is sometimes called “surface area.” It is about how much equipment is connected to the internet, or other networks including office networks, as well as exposure within the plant. The best way to protect an OT network is by limiting internet exposure. In general, the less internet connectivity, the safer the network.
Two Types of OT Network Threats
In the world of OT network security, there are two main types of threats. To consider each type, a great analogy is to consider the steps taken to protect a piece of personal property, such as a bicycle. The first type of threat is opportunistic attacks, similar to leaving a bike out in the street, where anyone passing by could just take it. Prevention of opportunistic attacks is generally a simple process, similar to putting the bicycle in the garage when not in use. With a firewall separating the internal network from the Internet and other networks, opportunistic attacks are dramatically reduced. However, the threat of a virus-infected computer spreading through the network remains and needs to be considered.
The second style of attack is targeted in nature. Targeted attacks are analogous to someone knowing there is a high-end bicycle in the garage and making specific plans to break in and steal it. Defending against targeted attacks is a much more complex process.
Securing an OT Network: Key Measures and Strategies
Implementing Fundamental Defense Tactics
Implementing fundamental defense tactics is crucial. One key step is deploying cloud-connected firewalls that offer automatic updates to fortify defenses against internet-based threats.
Deploy Cloud-Connected Firewalls
A critical approach involves configuring the firewall to operate differently from most IT networks. Instead of allowing all communications and subsequently blocking potential threats, the firewall should be programmed to function in a more restrictive manner.
Configure the Firewall for Restrictive Operation
This means stopping all communications by default, except for those that are explicitly known and trusted. In essence, the typical IT network setup is reversed. By blocking everything and permitting only the specifically authorized and recognized communications, a robust layer of protection is established, ensuring that unverified sources and potential threats are kept at bay.
Restricting Communications in OT Networks
The communications within OT networks are typically highly structured and specific, minimizing the need for extensive data exchange with external sources. Remote access support is a common requirement, and certain devices may necessitate internet connectivity for updates.
Restrict Access to Essential Features
However, it is advisable to restrict access to only the essential features. For maximum security, it is prudent to avoid connecting your OT network to the internet entirely. By doing so, you significantly reduce your exposure to potential external threats, enhancing the overall security of your network.
Air Gapping for High-Security Environments
For certain critical environments, especially in high-security production facilities, the practice of air gapping is the go-to solution. This entails physically isolating the entire system with absolutely no connections to the outside world.
Physical Isolation of the System
Some of Cornerstone Automation’s customers have chosen this approach due to the paramount importance of security. While it may reduce operational convenience, the trade-off is a significantly enhanced level of protection. In such cases, the only means of infiltrating the network is to either gain physical access to the system itself or compromise a device that, at some point, connects to this sealed-off network. This stringent isolation ensures a formidable barrier against external threats and unauthorized access, making it a choice strategy for safeguarding highly sensitive operational technology environments.
A Cautionary Tale: The Harrowing Experience of a Targeted Ransomware Attack
The security of an OT system is critical, as it can significantly impact its operation. To highlight the seriousness of these risks, let’s explore a real-life scenario that occurred within the network of a Cornerstone customer. This serves as a reminder that such attacks can happen unexpectedly, and in this case, it is not entirely clear whether the attack was carefully planned or just an opportunistic incident.
Factors for Success in an OT Attack
The success of this type of attack hinges on certain critical factors. To breach an OT network, the attacker typically has access to administrative rights, allowing them to wield considerable control over computer systems and network infrastructure. Alternatively, they might exploit vulnerabilities in a computer to escalate their privileges, gaining unauthorized access to the heart of the network. Once inside, the attacker’s actions can reverberate like shockwaves, infiltrating and compromising various components within the network.
Ransomware Attack: The Specifics
In this particular case, it was a ransomware attack – a menacing digital weapon that encrypts the data on every connected computer’s hard drive. The attackers hold the decryption key hostage, effectively locking the victim out of their own systems. PLCs (programmable logic controllers) were spared due to their unique architecture, but the assailants targeted Windows computers with ruthless efficiency. The ramifications were severe, as the victim’s SCADA package, Ignition, which relies on Windows, was incapacitated. This loss of visibility into their operations added an extra layer of complexity, despite still being able to run machinery. Moreover, the ransomware crippled the victim’s business systems, impacting order fulfillment and disrupting planning processes.
Choices for Victims of Ransomware
Confronted with ransomware, victims are left with three grim choices. They can yield to the demands of the attackers, a decision akin to negotiating with terrorists, with no guarantee of recovery. Alternatively, they may rely on meticulously maintained backups to restore their systems to a pre-attack state. Lastly, starting from scratch becomes the arduous, but sometimes necessary, path to recovery. This sobering narrative serves as a stark reminder that in the world of OT network security, vigilance and preparedness are paramount, as the cost of complacency can be nothing short of devastating.
Future Trends and Concerns
In an age where more data is being channeled into the cloud, it is crucial to recognize the potential vulnerabilities this shift can introduce into your OT network. While a firewall provides substantial protection, the susceptibility of your OT network increases if the cloud host were to be compromised, highlighting the importance of robust security measures.
As the deployment of OT networks for enhanced connectivity becomes more widespread, the likelihood of opportunistic attacks also rises. Thus, safeguarding your OT network is not only imperative but an evolving necessity.
Cultivating a resilient OT network security strategy is just the first step. Embracing the convergence of IT and OT through Smart Manufacturing and IIoT holds the potential to transform your operations, offering insights, efficiency, quality, and safety. The integration of enterprise business systems with plant floor control systems not only ensures security but also leads to significant cost reductions and a formidable competitive edge.
Cornerstone Automation’s OT Networking Expertise
Cornerstone Automation is one of the few system integrators offering OT expertise to customers. Their engineers have a thorough understanding of TCP/IP and Ethernet protocols, hardware, and media, to help customers create a safe and secure OT network. At the start of an engagement, it is common for customers to have no backups for PLCs and other programs, as well as incomplete machinery documentation.
The Cornerstone Automation team has the expertise to make these critical device backups, as well as implement and maintain firewalls. Another skill set is recreating documentation from scratch for equipment that previously had none or fixing broken equipment with little to no documentation. This process can be tedious but can often prove less expensive than purchasing new equipment.
Reach out to us today to unlock your industrial operation’s full potential. Ensure both the security and efficiency you need to thrive in this ever-evolving landscape.