Network Segmentation Security Best Practices: Reduce Blast Radius of an Attack

While network segmentation is known as a go-to tool in healthcare cybersecurity, it has a misunderstood role. Segmentation works well as part of your risk mitigation strategy—but it’s not the only tactic. When employed appropriately, in conjunction with other relevant strategies, network segmentation reaches its full protective potential.

Healthcare networks need that protection now more than ever. IT departments are struggling to retain enough skilled labor, and the size and number of attacks are increasing, with tens of millions of people affected and a 94% increase in attacks from 2022 to 2021 alone. A particularly disturbing trend is the rise of ransomware, which holds a health provider hostage over access to its data. Healthcare cybersecurity is at a crux.

As a stirring example, one healthcare company recently agreed to pay $2.7 million in the aftermath of a breach that leaked massive amounts of private patient data. The ensuing spending included measures to prevent a recurrence—but it would have cost less to implement an effective security program beforehand.

Investment in network segmentation security before disaster strikes is essential—but you also need to make sure you invest in the right security. Organizations need a reliable system to manage their connected devices, like Asimily cybersecurity solution for medical and IoT devices.

Why Network Segment?

Segmenting a network restricts the attack surface to minimize risk. An unsegmented network has far more targets available for attackers, and it’s also easier to spread from one compromised target throughout the network. By using network segmentation security best practices, you naturally limit the blast radius of an attack.

Think of segmenting your network like running a hotel. A hotel doesn’t just leave all the rooms open to each other; rather, it has different access rules for each area. A divided network gives you increased control over who has access to which resources and lets you monitor activity closely. It’s a way to protect IoT medical devices running on out-of-date operating systems too. This, in turn, helps make it easier for healthcare organizations to comply with regulations and prevent or mitigate security breaches.

But while network segmentation is a valuable approach to overall network security, it has its limits. Segmenting a network properly requires considerable attention. You have to make individual profiles for different devices, and you may encounter errors or different policies within a range of devices. If you create a profile that is too restrictive, devices may partially or even completely stop functioning if they can’t make the network connections necessary, which can be very difficult to remedy. Network segmentation security also requires long-term maintenance—and the process is subject to human error.

Network Segmentation Security Best Practices

Before you begin setting up your controls to segment your healthcare network, you need to thoroughly understand your organization’s IT infrastructure. Without this foundational knowledge, you risk doing more harm than good. Asimily’s risk remediation platform develops a detailed layout of risks. With this you can identify and focus on the important risks to the internet of things (IoT) in healthcare.

Let’s look at some general best practices to consider when assembling your network segmentation security plan.

Develop a Deep Understanding of Device Security Issues

Learning more about IoMT security lets you precisely apply network segmentation. Asimily analyzes the paths that attackers can use to reach a device, revealing less-obvious vulnerabilities and showing which ones are less of a risk than they might appear. Asimily also keeps a repository of manufacturer information on thousands of medical devices. This complements tested workarounds to give you the upper hand over connected device vulnerabilities.

Even before you start patching or segmenting, a risk assessment identifies connected IoT medical devices and their vulnerabilities, helping you prioritize which devices need protection most. Additionally, controlling who can access subnets alongside the detection and mitigation of threats minimizes your attack surface from the start.

Maintain a Consistent Network Audit Schedule and Process

Networks are dynamic structures, constantly undergoing changes. It’s tough to keep pace with the rapid modifications to devices, software, and users on the network. By auditing regularly, you can find and fix vulnerabilities before they become serious problems.

Sharing the audit results with team members makes it easier to deploy improvements. You can also compare results to previous audits to spot any oversights.

Work with data from Asimily to see which devices are on your network and what risks they carry. This lets you determine which threats are relevant—and pursue smart security policies like segmenting related assets in a group.

Healthcare organizations should audit at least once or twice a year to protect sensitive data, identify hardware issues, and improve network security and operational efficiency.

Network Segmentation Security May Be the Last Resort Strategy

One of the main mistakes that people make regarding network segmentation is to see it as the first or only technique to use. However, networks can employ varying levels of segmentation security.

Since it takes time to segment a network, there’s a tradeoff in the costs (management difficulty) versus the rewards (increased security) of what you segment. Not every single device needs its own private space. The benefits of Asimily Insight include telling you which devices truly need remediation: those most critical to patient outcomes or most at risk of exploitation.

You can then use other applicable techniques like patching or exploit mitigation based on Asimily recommendations to protect against the most threatening situations, only turning to network segmentation as a last resort for specific devices.

Better Healthcare Cybersecurity With Asimily

Network segmentation is one of the most useful methods to ensure healthcare IT security—but far from the only solution. Separating off some parts of the network can help you reduce attacks and limit the blast radius of attacks that do occur. But in order to be truly effective, you need to use segmentation in conjunction with other mitigation strategies.

A comprehensive solution like Asimily understands that segmentation is just one tool in the toolkit, and plans mitigation accordingly. Rather than just blindly segmenting networks to such an extent that the practice becomes counterproductive, Asimily provides highly relevant information on device risks. Then you can safely and affordably segment what matters.

Asimily’s security solutions are designed specifically for healthcare organizations, protecting over 20 million devices at over 2,300 sites. Are you ready to give your IoMT devices the security they deserve? 

To learn more about Asimily, download our Beyond Zero Trust: 8 steps to Holistic IoMT Security ebook or contact us today.

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