Cybersecurity for Industrial Control Systems: Best Practices and Solutions
Since the beginning of the industrial revolution, businesses in the manufacturing, transportation, and energy sectors have depended on an ever-evolving set of technologies to fuel growth. Early on, industrial machines were simple. However, over the years, industrial equipment increasingly began incorporating computerized components that vastly improved performance and capabilities. That also introduced an array of new vulnerabilities to the machines themselves.
Today, most industrial equipment is not only computerized but also internet connected. As a result, years of unpatched vulnerabilities now lie open to attack. Worse, hackers have taken notice. Back in 2022, an array of US government agencies jointly released an alarming warning. It indicated that they found evidence of a new powerful hacking toolkit in the wild, aimed at enabling attacks on industrial control systems (ICS).
That warning sent a clear message to businesses which rely on internet-connected ICS, stressing the importance of building robust security systems and procedures to defend against attacks. To help with that endeavor, the following article provides a step by step action plan which can act as a guide for businesses who would like to harden the defenses of their ICS-heavy networks.
1. Device Discovery and Mapping
One of the key problems businesses face when they attempt to secure their ICS assets is asset sprawl. Simply put, this means ICS assets are now so common and interwoven into larger systems that businesses may not have adequate visibility into where they all are in their larger networks. Therefore, the first step in hardening ICS defenses is to conduct a thorough discovery process.
That process must include active network discovery as well as on-site inspections. This is essential because there may be many ICS assets in use with outdated operating systems and non-standard management protocols. As a part of the discovery process, it is a good idea to build a comprehensive asset database that includes information about the vendors, serial numbers, model numbers, and software versions of every ICS asset on the network.
2. Known Vulnerability Discovery
The next step in the process is to use the completed device database as a basis for known vulnerability discovery. The reason is simple. Most ICS hardware, especially if it is not recent, will likely have a long list of known vulnerabilities associated with it. Fortunately, as many as 65% of all known ICS vulnerabilities already have patches available to address them. Therefore, enumerating all the known vulnerabilities will inform the next steps, including the software update, patching, and the design and deployment of further mitigation methods for unpatched vulnerabilities.
3. Design and Implement a Patching Program
With a list of known vulnerabilities in hand, the next thing to do is design and implement a patching program. This should begin with a phased rollout to test and apply the patches of known vulnerabilities discovered in the previous step. It is important to approach the task with care, as the application of patches to production machinery does come with some risks. To mitigate these, it is a good idea to conduct laboratory simulations or digital twin simulations before updating any real-world hardware.
After all ICS equipment is up to date, the next step is to design a process to keep the updates coming. In some cases, automated patch management solutions could help accomplish this. However, certain older ICS hardware may require manual scheduled interventions to apply new updates. Therefore, creating a process that covers all the bases is key.
4. Design and Implement Security Controls
A patching program alone is not enough to secure a network that includes large quantities of ICS assets. There are simply too many vulnerabilities for which no patches exist, and an unknown quantity of undiscovered vulnerabilities that an attacker may find during a probative attack. Therefore, it is necessary to design and implement a robust system of security controls to further protect ICS assets.
This should start with an effort to minimize user rights to comport with the principle of least privilege (POLP). Next, it should set and enforce strong password policies for all remaining user access. This will cut off a common attack vector by denying an attacker easy access to any privileged accounts.
The next phase of planning must address remote access. This must include examining access to ICS assets by 3rd parties and contractors. The idea is to close as many points of access as possible, and then harden the rest. This is best accomplished by enforcing the same access and password standards that apply to internal users and adding layers of authentication and encryption to all remote access connections.
5. Develop Incident Response Plans
Lastly, it is critical to assume that an attack is still possible, despite the defensive measures now in place. To deal with that eventuality, it is important to develop incident response plans that adhere to industry best practices. In general, this means identifying the types of attacks that could occur and creating a step-by-step plan for each, that will guide every employee’s actions if it comes to pass. Each plan should include details on carrying out the following steps:
- Identifying and categorizing the attack
- Halting the attack and containing the attacker and damage
- Eliminating threats and preventing follow-on attacks
- Recovering from the attack and restoring normal operations
- After action analysis, education, and security enhancement
As a part of an incident response plan, it is also a good idea to identify key technology partners and cybersecurity specialists to turn to in an emergency. This could include partnering with cybersecurity specialists like Outsource IT to help with security monitoring, proactive defenses, and incident response. That is often more cost-effective than trying to build a cybersecurity department with the requisite expertise to handle the job.
It is also a good idea to develop worst-case scenario plans to handle major disruptions that could result from a successful attack on an ICS asset or assets. These should include procurement of backup hardware for mission-critical systems, and data and setting restoration dress rehearsals to test and practice recovery procedures. This is another area where digital twin technology could be of assistance. It would allow for scheduled recovery simulations that do not require downtime or meaningful disruption of business activities.
Your ICS Security Partner
As attackers gain more awareness of the vulnerabilities inherent in major industrial systems, they will ultimately turn their attention towards exploiting them for profit. Additionally, nation-state actors remain a persistent threat to ICS-dependent businesses and infrastructure providers in multiple industries. Therefore, it is imperative that business organizations at risk take action to head off potential threats before they become real-world attacks.
Of course, Outsource IT can help any business looking to improve their ICS security. Our cybersecurity specialists can act as consultants or front-line partners in the fight against ICS threats. To get started, simply contact one of our knowledgeable account managers and ask them about our ICS security offerings today.