Complete Guide to Industrial Secure Remote Access

By Sectrio
February 19, 2024
Complete Guide to Industrial Secure Remote Access


Secure remote access has become crucial for industrial operations, offering increased efficiency, reduced downtime, and enhanced security. However, it requires balancing convenience with robust protection against cyber threats. Implementing multi-factor authentication, encrypting data, and restricting access are key best practices. Organizations must also consider the unique needs of industrial control systems and ensure all stakeholders, from executives to employees, play their part. By prioritizing security and following best practices, companies can reap the benefits of secure remote access while mitigating potential risks.

Critical infrastructure relies heavily on the effective functioning of industrial control systems. To ensure their optimal performance and constant availability, it is necessary to shield these systems from both intentional and unintentional disruptions that could adversely affect their operations. 

Historically, the safeguarding of these systems involved maintaining a clear separation between operational platforms and external networks. Additionally, access to control functions was restricted to authorized personnel with physical access to the facility.

However, in the present scenario, the evolving needs of businesses, such as the demand for increased and faster online access to real-time data while utilizing fewer resources, have prompted the widespread adoption of modern networking technologies. 

This rapid deployment has interconnected previously isolated systems, allowing asset owners to enhance business operations and reduce costs related to equipment monitoring, upgrades, and servicing. 

This newfound connectivity has introduced a novel security challenge, necessitating the protection of control systems from cyber incidents.

An important aspect of addressing this challenge involves understanding how operational assets are accessed and managed. If remote access management is not well comprehended or poorly executed, a control system’s cyber security posture can be compromised. 

Know more: Sectrio’s solutions for Industrial Secure Remote Access

Yet, similar to contemporary cyber security measures, applying established remote access solutions may not flawlessly align with the control system’s environments. The specific requirements for availability and integrity, coupled with the distinctive characteristics often found in purpose-built systems, demand guidance in establishing secure remote access solutions for industrial control systems environments.

This blog centers around best practices and serves as a valuable resource for developing remote access solutions customized for industrial control systems. It draws upon common good practices from standard information technology solutions, contextualizing them within the control system’s environments. 

Additionally, it offers insights into deploying remote access solutions that address the unique cyber risks associated with control system architectures. The ultimate goal of this write-up is to provide guidance on developing secure strategies for remote access in industrial control system environments.

What Is Remote Access in Industrial Control Systems (ICS)?

Remote access is a straightforward concept. It’s essentially the ability of an organization’s users to reach its private computing resources from external places beyond the organization’s premises. However, remote access is more than just reaching data or systems; it’s about getting into a network that is safeguarded, both physically and logically, from a system or device outside of that network.

So the working definition for remote access in this guide is: “The capability for an organization’s users and operators to connect with its private computing resources, data, and systems residing within a physically and/or logically protected network from external locations that may be considered outside that organization’s network.”

The security features and functionalities of remote access are designed to establish secure electronic pathways. Providing authorized and authenticated entry into a trusted network from a location that might otherwise be deemed untrusted. In our definition, this trusted network would be identified as the control system network.

What Is the Importance of Industrial Secure Remote Access?

In the complex world of business operations, ensuring secure remote access to vital systems and sensitive assets can be challenging. These assets, including industrial control systems and the infrastructure housing sensitive data, play an essential role in the smooth functioning of most companies. 

Maintaining their online presence and ensuring safe operations is not just a priority; it’s crucial, as any disruption not only translates to hefty financial losses for a company but also jeopardizes human safety.

One approach often taken is to tightly control access, imposing complex requirements for anyone seeking entry. Imagine the logistical and financial burden of having to be physically present on a remote oil rig in the harsh North Atlantic winter to provide routine support for a critical system. To avoid such impractical scenarios, the alternative is often to grant more access than is necessary, extending trust to both individuals and devices. 

However, this leniency can inadvertently allow third parties, like contractors and maintenance teams, to access more than what’s intended, amplifying risks and broadening the company’s vulnerability to cyber threats.

Recognizing the substantial threat that cyberattacks pose to safety, operational uptime, and overall performance, executive leadership teams are now placing a renewed emphasis on securing critical access. 

Striking a balance between security and convenient access is the mission of security professionals across various industries. The goal is to enable the right level of access while simultaneously implementing crucial security controls, ensuring that users don’t find themselves compromising on security or convenience.

How Does Industrial Secure Remote Access Work?

Secure remote access serves as a tool to enhance industrial optimization, allowing your team to connect to ICS remotely through virtual desktop interfaces. Essentially, it replicates your plant’s systems, enabling operators and managers to access crucial factory floor data through a virtually direct link to SCADA, HMIs, PLCs, IACs, and other systems.

As network integrators, Sectrio strongly advises ensuring the resilience and security of your ICS access. This involves implementing a combination of secure industrial connectivity systems, processes, and policies rather than relying on a single technology claiming self-proclaimed security. 

Critical elements of a secure remote access model may cover:

1. Multi-layered Security

To shield data and assets from potential threats, you must deploy cybersecurity measures and systems at every level of your production layout.

2. Agile Connectivity and UX

Accessing your ICS should be swift, easily manageable, and sleek, ensuring productivity.

3. Compatibility

Systems should comfortably integrate and establish compatibility to prevent security gaps within interconnected apps, platforms, and devices.

Adding a new remote access connection to industrial control systems requires careful consideration. We recommend involving expert consultants in the decision-making process to customize the solution and effectively secure your IT and OT networks and industrial assets.

What Is Needed to Execute a Secure Remote Access?

Embracing zero trust is the key to a secure remote access solution. It’s not just a fancy phrase; it’s a crucial strategy. The industry faces staggering losses, around $100,560 million per minute when productive systems halt due to unexpected maintenance, system intrusion, or malfunctions. 

And that figure doesn’t even account for the ransoms demanded by hackers. Zero trust is like a shield, a secure network architecture model that works on the principle of “never trust, always verify.” It’s customized to safeguard modern industrial environments by using techniques like network segmentation, preventing lateral movement, deploying Layer 7 threat prevention, and simplifying user-access control in a detailed manner.

In the pre-2010 era, static defense mechanisms gave intruders plenty of time to dissect your network for vulnerabilities. The landscape shifted during the COVID era, altering the administrative processes underlying most remote access systems. 

To uphold control and security in industrial networks, we need strategies like per protocol – per port whitelisting, role-based access control, task-specific workstations, and VDIs, Moving Target Defense (as recommended by NIST 800-150 v2), and standardized access and approval processes, among other essential measures.

Additionally, features such as disposable virtual desktops, whitelisting (defining access based upon time, user, protocol, and device), end-to-end encryption, external internet and inbound ports blocking, SDPs for remote access, scheduling (setting access windows in advance), automated recording, multi-factor authentication, and one-click enforcement (requiring MFA or virtual desktops for your users) serve as valuable extras. 

These elements enhance control over identity verification, visibility, and action management within your industrial control systems.

What Are the Benefits of Industrial Secure Remote Access?

Enhancing production efficiency has never been easier with industrial secure remote access. This smart solution augments the production pipeline by securely providing access to real-time manufacturing data from every system on any device for those authorized to use it. 

It’s not just about convenience; it’s a game-changer that makes virtual commissioning and predictive maintenance a no-frills process. The result? Cost savings by minimizing unplanned downtimes, creating a smoother production flow, and ultimately impacting the bottom line positively.

In many industrial setups, a significant chunk of operating revenue goes into employee labor costs, a part of the overall operations and maintenance expenses. The challenge is often the unpredictability of when an operator might need to attend to a machine. 

This uncertainty leads to the need for multiple on-site operators around the clock, escalating costs. Factor in the additional expenses of experts traveling between locations, and the numbers climb even higher.

The solution lies in secure industrial remote access systems. They empower operators to address issues instantly through secure virtual desktop interfaces without being physically present. 

This not only reduces labor costs but also brings down overall O&M expenses. The goal isn’t to eliminate 24/7 presence, as it may be essential for certain industrial setups. However, with secure industrial remote access, a small team of 2–3 people can efficiently handle the workload that would otherwise require 7–10 workers. 

It’s all about optimizing resources, getting more done with fewer employees, and improving their quality of life.

Compliance with the regulations for contractors is comfortably integrated into the implementation of secure remote access. As the name suggests, security is a must in these systems, ensuring the safeguarding of industrial data and assets. 

When you embrace secure remote access, you’re essentially implementing a plan to prevent and mitigate attacks from intruders and maintain stability in ICS. With features like encryption, user authentication, and screen recording, you establish strict control over data access, ensuring it’s limited to authorized accounts, unreadable to intruders, and providing plant managers with a complete view of remote activities in the ICS through virtual desktop interfaces.

Who Bears Responsibility for Ensuring Secure Remote Access?

Securing remote access isn’t a one-person job—it’s a team effort that demands commitment across the board. To make it work flawlessly, executives and cybersecurity experts play a crucial role in setting the tone. 

They lead in developing comprehensive policies and standards that align with all internal activities. Think of it as the roadmap everyone follows to keep the virtual doors locked and guarded.

Next, the IT teams step in, whether in-house or brought in through external partnerships. Their responsibility revolves around the minute details of software systems and applications. They ensure the technicalities are up to par and keep a vigilant eye on the tools that safeguard remote access. 

Troubleshooting becomes their expertise, resolving issues swiftly to maintain a secure and uninterrupted connection.

Finally, the employees themselves have an important role to play. They’re not just users but the frontline defenders of secure remote access practices. Being accountable for how well they adhere to these practices ensures that the entire system functions like a well-oiled machine. 

It’s a collective effort where each member, from the top brass to the everyday team player, holds a piece of the security puzzle, making the whole organization a fortress against potential threats.

How to Create a Secure Remote Access Environment?

To safeguard every user, regardless of their location, organizations should prioritize the basics of remote access security by using these effective 7 steps:

  1. Installing reliable antivirus software on all devices, whether they are connected remotely or within the organization
  2. Monitoring remote access ports closely, either limiting their usage or rigorously for suspicious activities
  3. Embracing multifactor authentication (MFA) as an extra layer to verify user identities
  4. Ensuring that existing VPNs are consistently updated to their latest versions
  5. Implementing logging and tracking tools to monitor IP addresses and log-in attempts
  6. Regularly reminding internal users of standard cybersecurity practices
  7. Enforcing company security policies and adhering to industry standards for overall compliance

Certain users, often called privileged users, hold higher-than-normal access privileges. These individuals, including power users, root users, software developers, consultants, maintenance engineers, and network and database administrators, can access sensitive or critical data.

To enhance security for these users, organizations should consider the following measures:

  1. Linking user roles with a specific user identity and aligning admin-level access with defined roles
  2. Restricting access to the minimum level of privilege necessary for completing a task
  3. Leveraging advanced access management tools, such as hybrid privileged access management software
  4. Implementing MFA for especially critical sessions
  5. Securing credentials needed for privileged sessions, with a preference for passwordless and keyless methods
  6. Conducting regular audits, logs, and tracking of mission-critical sessions, optionally recording them for reference
  7. Monitoring and tracking automated application-to-application connections
  8. Ensuring secure file transfers and transmissions to and between servers
  9. Upholding company security policies and ensuring adherence to industry standards for overall compliance

Once these foundational practices are in place, organizations can fortify themselves against potential threats and delve into advanced cryptography, exploring additional best practices for secure remote access policies.

Top Recommendations for Industrial Secure Remote Access Policies

ICS operates differently than typical IT systems, necessitating a specialized security approach. Unlike IT systems, ICS utilizes proprietary operating systems designed for almost continuous operation, interacting with real-world inputs through field bus connections. These controls prioritize availability, aiming for nearly constant uptime.

While some IT security standards apply to ICS, additional considerations are vital due to differing risk concepts. In ICS, the primary focus is on the risk of life, equipment, or product loss rather than data or operational failure. Hence, priorities in ICS differ; availability and safety take precedence over security.

In OT, where ICS is concerned, availability and safety surpass security matters. Occasionally, these priorities may conflict during the design and operation of a control system.

Several guidelines and standards, such as IEC62443, NIST SP800, and ISO27001, address industrial cybersecurity. 

For secure remote access to ICS, consider the following recommendations:

1. Identity

1. Apply the recommended password policy in the PLC

Secure the machine’s configuration by implementing a robust password policy in programmable logic controllers (PLC) for the ultimate defense.

2. Change default passwords

Change default passwords during the initial device configuration to prevent unauthorized access, as default passwords are commonly known in the industrial automation community.

3. Implement multifactor authentication (MFA)

Integrate MFA as a best practice for remote access, adding an extra layer of security. MFA mitigates the risks associated with password vulnerabilities, providing a stronger defense against unauthorized access.

While MFA enhances security, it’s essential to consider the balance between security and practicality in emergencies, where a quick response is crucial. Choosing the most suitable solution for each scenario is recommended for effective implementation.

2. User Management

1. Ensure unique identification and authentication

Assign each user a unique identification and authentication, enabling swift account revocation if needed (e.g., when an employee departs). Implement configurable password policies managed by administrators, with options for minimum length, character types, and lifetime. Ensure concealed feedback during password entry for added security.

2. Define individual user rights

Centrally manage user access rights at the server level, providing an additional layer of security. Users should belong to groups with assigned roles for accessing routers or groups. Enable unified account management, allowing authorized users to add, activate, modify, disable, and remove accounts. Administrators should have the ability to temporarily block user access without deleting profiles.

3. Restrict OEM access to machines only

Configure the system to segregate machine networks from the overall network, ensuring original equipment manufacturers (OEMs) only access the machines they are responsible for. This involves assigning different IP addresses to machine network nodes.

4. Avoid using control devices as VPN Hosts

Refrain from using control devices like PCs, HMIs, or PLCs as VPN hosts to prevent resource reduction and performance degradation. Use external routers as a boundary to filter packets, protecting control systems from direct impact during denial-of-service (DoS) events.

5. Allow outgoing connections only

Permit only outgoing connections from trusted to untrusted zones, avoiding exposed inbound firewall ports on the Internet. To ensure secure remote access services, utilize secured outbound VPN tunnels authenticated and encrypted with HTTPS.

6. Encrypt all traffic

Implement strong encryption for remote support users connecting over the Internet, using protocols like VPN, application servers, or secure HTTP access. Authenticate with robust mechanisms like token-based multifactor authentication, utilizing widely accepted standards like X.509-based PKI.

4. Limit Connectivity

1. Higher-level firewalls and filtering

Restrict access to device IP addresses and ports through configuration, including ethernet and gateway service limitations. Perform this filtering outside the router.

2. Keep router IP address hidden

Conceal router IP addresses from the public to prevent easy scanning by hackers. Use private VPN addresses instead of public IP addresses to connect to the router.

5. Update Your Defenses

1. Regularly update devices

Keep devices updated with the latest official firmware and security patches, as per manufacturer recommendations. Stay informed about vulnerabilities through ICS-CERT for timely patching.

2. Enable full reset to factory settings

Ensure routers can be fully reset to factory settings, covering all aspects like passwords, device identification, LAN IP addresses, and more. This helps restore the device to its original state in cases of unusual behavior.

3. Configure remote access based on real needs

Customize remote access configurations according to actual security needs versus availability requirements. Consider the balance between security procedures and the necessity for quick connections in real-time operations.

4. Audit connections and changes

Implement a system capable of auditing events related to access control, errors, operating systems, control systems, backup and restore, configuration changes, potential reconnaissance activity, and audit logs. Maintain detailed records with timestamps, sources, categories, event types, event IDs, and results.

5. Ensure high availability of remote access service

Demand high availability from the cloud service provider, especially during emergency operational support. Strengthen service level agreements (SLA) with monitoring systems, alarms, and on-duty engineers available 24/7/365.

Industrial Secure Remote Access Solutions with Sectrio

Explore the unified world of secure remote access solutions with Sectrio. Are you seeking a comprehensive approach to fortifying your business’s remote access landscape? Sectrio’s zero-trust access management seamlessly integrates with any IT setup.

Sectrio unfolds a panoramic view of your entire organizational framework for administrators. It operates on principles such as least privilege, zero trust, and just-in-time, providing end-to-end visibility. Through a centralized interface, admins can activate session recording, manage privilege roles, tackle challenges, assess real-time metrics, and ensure compliance with security standards like NIST, ISO 27001, and PCI-DSS.

This solution handles all your vital credentials, including privileged passwords and encryption keys. Industrial automation, manufacturing, and operational technology facilitate a smooth transition to efficient, cost-effective, passwordless, keyless access management. 

For insights on how Sectrio can streamline your secure remote access toolkit, connect with us for easy monitoring and maintenance.

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Secure remote access has become crucial for industrial operations, offering increased efficiency, reduced downtime, and enhanced security. However, it requires balancing convenience with robust protection against cyber threats. Implementing multi-factor authentication, encrypting data, and restricting access are key best practices. Organizations must also consider the unique needs of industrial control systems and ensure all stakeholders, from executives to employees, play their part. By prioritizing security and following best practices, companies can reap the benefits of secure remote access while mitigating potential risks.

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Secure remote access has become crucial for industrial operations, offering increased efficiency, reduced downtime, and enhanced security. However, it requires balancing convenience with robust protection against cyber threats. Implementing multi-factor authentication, encrypting data, and restricting access are key best practices. Organizations must also consider the unique needs of industrial control systems and ensure all stakeholders, from executives to employees, play their part. By prioritizing security and following best practices, companies can reap the benefits of secure remote access while mitigating potential risks.
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