SecureTrust Cybersecurity

How Microsegmentation Prevents Ransomware Attacks

Preventing ransomware with microsegmentation

Microsegmentation prevents ransomware attacks by isolating critical assets, limiting lateral movement across a network, providing granular least privilege access, enables rapid isolate, simplifies recovery, improves cyber resilience, and reduces the blast radius.

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Ransomware attacks have become an increasingly dangerous threat facing organizations of all sizes.

Ransomware leverages lateral movement techniques to infect and encrypt as many endpoints and servers as possible.

On flat corporate networks, attackers have an open highway enabling this lateral propagation between workloads.

Once entrenched, ransomware will methodically encrypt not just data files, but also backups, applications, databases, and more.

Microsegmentation offers a powerful set of capabilities to harden defenses and minimize the business impact of ransomware.

Computers protected by a bubble of security

Isolate Critical Assets

One of the most important ransomware protections microsegmentation provides is the ability to isolate an organization’s most sensitive and critical data, servers, databases, and systems into secure zones completely inaccessible from the rest of the corporate network.

  • Identify crown jewels: Perform risk analysis and discovery to classify and prioritize the most critical assets, like finance systems or customer data, for isolation.
  • Harden zones: Configure hardened network segments containing must-protect assets and provide dedicated infrastructure. Tightly limit ingress/egress points.
  • Restrict access: Only allow connections into isolated zones from authorized systems like jump hosts using strict access controls. Block all other communication.
  • Monitor traffic: Any lateral connections attempted with critical zones should get heavy scrutiny as potential unauthorized access attempts.

By proactively isolating the highest value assets, organizations limit the damage if ransomware gets into other areas of the network critical systems have additional layers of protection.

Learn More: Microsegmentation Best Practices

Exhausted female hacker

Limit Lateral Movement

Network segmentation fundamentally prevents threats like ransomware from moving laterally and propagating across an organization by restricting communication paths between endpoints, servers, and network zones.

  • Restrict east-west traffic: Microsegmentation strictly limits what lateral east-west traffic is allowed across the network using firewalls between segments.
  • Deny by default: Access controls explicitly allow only essential traffic flows. All other intra-network traffic is denied by default.
  • Application-aware controls: Segmentation can limit which specific applications or services connect between zones, not just address pairs.
  • Authenticate users: Incorporate user-based access controls to prevent malware or compromised accounts from freely moving laterally.
  • Monitor flows: Unapproved connection attempts between hardened zones and other areas are clear incidents warranting alerts and investigation.

With micro perimeters erected throughout the network, ransomware’s capability to infect large swaths of an environment is substantially reduced and controlled.

Learn More: Top Benefits Of Microsegmentation

Analyze network data and traffic flows

Granular Least Privilege Access

Microsegmentation allows extremely granular least-privilege access controls to be defined between zones, limiting which specific accounts, applications, services and devices can communicate with each other.

This fundamentally reduces the attack surface for ransomware propagation.

  • Analyze data flows: Use data flow analysis to determine precisely what connectivity various workloads require. Explicitly allow just these flows.
  • Implement strict ACLs: Access control lists between segments grant only explicitly approved connections. Anything not defined as allowed is automatically denied.
  • Tighten security over time: Continue to monitor access patterns and decrease exposed pathways to align with the principle of least privilege.
  • Mask critical assets: Avoid exposing IPs or ports for crown jewel zones. Use proxies and jump hosts to obscure.
  • Integrate NAC: Incorporate network access control to validate endpoint security posture before granting access.

With granular microsegmentation, malicious actors have far fewer avenues for lateral movement, even if they breach perimeter defenses.

Learn More: How Zero Trust And Microsegmentation Work Together

Enable Rapid Isolation

If ransomware is detected within a specific microsegment, administrators can instantly isolate the impacted zone to prevent further propagation of the infection to other areas of the business.

  • Automate isolation capabilities: Make sure segmentation solutions provide easy ways to immediately isolate compromised zones with a few clicks or API calls.
  • Document response processes: Document incident response runbooks detailing how to isolate high-risk segments. Train personnel.
  • Implement quarantine zones: Define dedicated quarantine network zones that compromised systems can quickly be moved to for analysis and remediation.
  • Confirm backups: Validate uninfected backups of data within impacted microsegments are available before isolation.
  • Buy time: Even brief isolation windows allow security teams to implement organization-wide containment controls like temporary Active Directory password resets.
Improve data recovery after a cyber attack

Simplify Recovery

With critical assets and data already logically isolated in hardened microsegments, relatively clean backups of these systems are readily available in the event of a ransomware incident. 

This makes restoration and recovery simpler for organizations vs. rebuilding from scratch.

  • Maintain recent valid backups: Schedule regular backups of critical systems and data within isolated zones. Test restoration periodically.
  • Physically isolate backups: Store backup media for isolated zones offline in physically secure locations to prevent corruption.
  • Focus protection efforts: More security resources can be dedicated to thoroughly protecting fewer critical systems and backups.
  • Reduce reliance on offline backups: With critical data access restricted via microsegmentation, less data may need to be archived offline.
  • Streamline restoration: Clearly documented segmentation architecture and data flows simplify restoring business functionality after outages.

Learn More: How To Implement Microsegmentation

Happy business executive

Improve Cyber Resilience

By leveraging microsegmentation to protect crown jewel assets and data within hardened zones, organizations are far less likely to pay ransoms to attackers.

They can simply restore from intact backups of critical systems maintained in isolation.

  • Avoid paying ransoms: Isolated backups reduce the temptation to pay ransoms even if the main production environment is compromised.
  • Maintain business continuity: With critical functions isolated, aspects of business operations may continue even when certain segments are disrupted.
  • Meet compliance requirements: Standards like PCI DSS require segmentation controls for cardholder data environments. This provides inherent protection against ransomware threats.
  • Protect customer data: Microsegmentation makes customer data breaches resulting from ransomware less likely, helping preserve customer trust.
  • Reduce costs: Time and expenditure associated with widespread infrastructure rebuilds, data restoration, legal liabilities, and reputational damage are reduced through resilient segmentation strategies.
Limit attack path of ransomware attacks

Reduce Blast Radius

By limiting lateral pathways, microsegmentation ensures ransomware compromises are far more contained.

Instead of infecting entire flat networks, ransomware will be restricted to the scopes of individual microsegments where it breaks in.

  • Limit the number of assets affected: If ransomware breaches a perimeter, fewer total endpoints, servers, services and data repositories will ultimately be impacted.
  • Reduce outage durations: Since fewer systems are disrupted, restoration and recovery timeframes are compressed.
  • Lower costs: Containment makes ransomware cheaper to remediate by reducing the number of assets and data that must be repaired or rebuilt.
  • Minimize business impact: With a smaller blast radius, fewer business functions will be impaired during outages. Revenue loss and customer impact will be minimized.
  • Constrain encryption: Encryption of files and data will be limited just to the compromised segment’s scope.


By taking a strategic approach to designing microsegmentation architectures aligned to critical assets, systems and workflows, organizations can effectively minimize the business impact of ransomware attacks.

Network segmentation dramatically reduces ransomware’s ability to propagate and exploit large portions of corporate environments.

It frustrates and contains such threats by erecting internal barriers to lateral movement.

Microsegmentation is a powerful capability for improving ransomware resilience.

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Rich Selvidge
Rich Selvidge
Rich Selvidge is the President, CEO, & Co founder of SecureTrust, providing singular accountability for all information security controls in the company.

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