Commonly known as ICS, industrial control systems run the world’s infrastructure. Government and private agencies have used ICS for decades to run industrial processes and critical infrastructure. ICS is responsible for the primary services, including power, water, and natural gas.

ICS has suffered from cyberattacks in the last couple of years. The first six months of 2021 witnessed a 41% spike in reported ICS weaknesses. And the number increases as new threats to OT security are rampant. Moreover, the IoT has also transformed the threats these systems face. This blog will discuss best practices for protecting ICS from cyber threats.

Need for Protecting Industrial Systems

The attacks and threats to operational technology security indicate a need to secure the networks and take measures that efficiently incorporate the layers of ICS. ICS systems automate and control energy, water, transport, health, and manufacturing, to name a few.

These systems once operated offline. The advent of the internet led to their development. ICS runs on proprietary protocols with custom software in individual and isolated networks to mitigate and control cyberattacks.

Why is the ICS a target? Due to being built years ago, ICS design did not include dealing with cyber threats. ICS is an easy target for attackers looking to penetrate OT security because most networks rely on legacy technology.

Due to this, they need more basic security measures common today, like authentication and encryption. A breach into an OT environment allows attackers to penetrate the organization and cause chaotic situations.

If OT networks lack optimal design, IT systems can become compromised. Companies must prioritize OT security to secure their essential infrastructure and the society that depends on it.

Millions of ICS today are connected to the internet for remote system maintenance, production data control, and more. However, while it significantly improves efficiency and effectiveness, it makes ICS vulnerable and an appealing target for cyber attackers. When ICS is compromised, it can lead to severe compromises in safety and security.

Due to rampant technological advancement, cyber threats are becoming more innovative and sophisticated, calling for a comprehensive and proactive approach to OT environment protection.

Best Practices to Protect Industrial Control Systems from Cyber Threats

Let’s delve into this detailed cybersecurity guide that covers steps you should take to protect ICS against cyber threats:

Industrial Control System Audit

To fully protect something, you need the knowledge of what you have. It is essential to carry out a comprehensive audit of your OT security. Here are the important factors to consider:

  • What protocols are in practice, what keeps everything connected, and who has the physical access?
  • The number of computers you have, their OS, their security, who has physical access, software, external connection, etc.
  • Do you have a Safety Instrumented System? Does it effectively integrate with your ICS?
  • What kind of controllers do you have, how can they be accessed digitally, and who can have physical access?
  • Existing kinds of sensors and actuators, their digital access, and who has access to them?

Devise a Risk Management Plan

After documenting everything, it is time to design a risk management plan. Create a document that everyone can follow. Again, this document would answer the questions regarding identification, responsibility, assessment, mitigation, and tracking. These questions shall include the following:

  • The number of ways your system can fail
  • The number of compromised processes in that case
  • If something fails, who will be responsible?
  • Who is responsible for ensuring minimal failures? Who shall assist recovery from failure? Who will install the new equipment when required?
  • Who would ensure compliance with the Risk Management Plan?
  • Which risks are insignificant and can be taken lightly without prompt action?
  • Which of the risks or failures are acceptable and have existing recovery plans?
  • Which failures or risks require planning and addressing?
  • How often do you update the system audit? Do you frequently evaluate system vulnerabilities? When and how the risk management plan is updated?

Plan and Fix ICS Vulnerabilities

After crafting a risk management plan, it is time to mitigate risks by reducing and eliminating weaknesses in your industrial control system, which includes modifying hardware, software, and operating procedure.

See how you can improve your current system and boost security. What are the latest operational technology security practices you can follow? What kind of equipment and skillset is needed to fix ICS vulnerabilities?

Use Multi-factor Authentication (MFA)

You should actively use MFA for all the external facing authentication portals and other sensitive services. MFA performs as an additional layer of security. So, even if cyber attackers guess a password, the accounts stay safe.

Make an Operational Technology Security Policy

While you fix your system vulnerabilities, you should also work on your OT security. Your IT team may already have a security policy, and so should you. It should not be IT vs. OT. Rather both should have the same direction toward the same security goals. However, applying the policies on industrial equipment would need some adjustments.

Make a plan for following the OT security policy. Measure and then enforce the best practices. Both the Operations and Management departments should team up and work together toward the same goal.

Prepare an incident response and disaster recovery plan

Each system could be partially foolproof. One should minimize risk as much as possible. But be prepared for a disaster even then. Taking the steps mentioned above could facilitate you in knowing about every weak component in the system.

The components susceptible to failure should have a recovery plan in case of failure. Moreover, developing an IR plan would ensure that the affected systems and personnel are trained regularly and assessed.

Offer Ongoing Employee Awareness Training

Employees from the entry-level to executive staff require appropriate training. All the employees should be able to recognize malicious attacks or intent and effectively respond when targeted.


Industrial control systems are crucial to our lives. Their security is imperative to the smooth functioning of society. One must understand the ongoing threats to ICS and take effective measures and implement them efficiently to mitigate risks to ascertain essential services continue to operate without glitches.