Microsegmentation: the decisive response against attackers’ lateral movement

September 22, 2025

Security neither begins nor ends at access points. Threats infiltrate, adapt, and move with alarming ease in increasingly distributed, dynamic, and complex technology environments. The adoption of hybrid and multicloud architectures, along with the rise of microservices and containers, has multiplied the internal attack surface, making control and visibility far more difficult.

In this scenario, one of the most critical risks is the lateral movement of attackers: their ability to advance silently within the network once they have compromised a vulnerable server, endpoint, or application. Instead of stopping at that initial target, they leverage internal connections and excessive permissions to escalate towards sensitive data, critical applications, or high-value business systems. This dynamic has been a determining factor in ransomware campaigns, industrial espionage, and advanced persistent threats.

Lateral movement is an attacker’s silent weapon, and microsegmentation is the line in the sand that stops it.

Microsegmentation has become one of the most effective measures to curb this type of threat. It allows organizations to control traffic between workloads, limit the spread of incidents, and contain their impact without compromising operational continuity.

■ At Telefónica Tech, we see this approach as a fundamental pillar for implementing a Zero Trust architecture, where every communication must be verified before it is allowed.

Thanks to the combination of granular visibility, adaptive control, and immediate response, microsegmentation not only strengthens resilience but also helps organizations trust their digital capabilities, maintain business continuity, and comply with increasingly demanding regulations such as the DORA regulation or the NIS2 directive.

Visibility: the foundation of microsegmentation

The first step in protecting a digital environment is to fully understand it. Microsegmentation provides complete and continuous visibility into communications between users, applications, processes, servers, and cloud environments.

Through a centralized dashboard, it is possible to build a dynamic map of all interactions within the infrastructure, showing which applications communicate with each other, how data flows to databases, and what external connections exist. This precise picture helps uncover hidden dependencies, unnecessary or misconfigured flows, and potential security gaps.

You can’t protect what you can’t see: microsegmentation delivers a full X-ray of internal communications.

This visibility is not only a technical advantage but also a key requirement in today’s regulatory landscape. Having clear, verifiable evidence of how internal communications are managed is essential to demonstrate control and governance to auditors and regulators.

Granular policies to block unauthorized movement

Once the organization has a detailed understanding of its digital ecosystem, microsegmentation enables the definition of highly precise security policies. Instead of relying on static rules based on IP addresses or network perimeters, logical controls are designed and aligned with the function of each application or service.

This means that each workload can communicate only with the resources it truly needs to operate. For example, an application server may access its associated database, but not another database or a different backup system. In this way, routes that an attacker could exploit for lateral movement are effectively closed.

Policies can be adapted quickly and scaled across hybrid and multicloud environments without redesigning the existing architecture. This makes adoption progressive and minimizes impact on critical operations.

With microsegmentation every workload speaks only to what it truly needs, shutting down the paths attackers rely on.

Immediate response and regulatory compliance

Microsegmentation not only prevents but also improves detection and response capabilities. By maintaining control over every communication flow, any unauthorized access attempt can be identified and blocked in real time. This drastically reduces containment time in the event of an incident and prevents an attack from escalating into a major crisis.

In addition, the ability to generate clear, exportable reports facilitates compliance with regulations such as DORA or NIS2, which require organizations to demonstrate operational resilience, incident traceability, and the application of least privilege principles. With microsegmentation, security teams can provide verifiable evidence that risks are being effectively managed.

By controlling every communication flow, organizations can block intrusions on the spot and prove resilience to regulators.

Use cases for microsegmentation

The value of microsegmentation becomes tangible in multiple business scenarios.

In the financial sector, for example, banks and insurers rely on core systems that require maximum protection. With microsegmentation, critical applications such as payment engines can be isolated from less sensitive environments, preventing an intrusion in a peripheral system from compromising the business core. Moreover, this granular control helps meet DORA requirements, which demand evidence of operational resilience and risk governance.
In the field of digital healthcare, hospitals operate connected medical devices and electronic health record applications, often supported by legacy systems that are difficult to patch. Through microsegmentation, these devices can be isolated and restricted to communicate only with strictly authorized servers, preventing them from becoming entry points for attackers and ensuring the availability of critical medical services.
In the manufacturing industry, where industrial control systems (OT) coexist with IT networks, microsegmentation makes it possible to clearly separate the two domains. Thus, an attack on the corporate network cannot spread to the production plant, ensuring the continuity of industrial processes even in the event of a cyber incident.
In multicloud environments, microsegmentation provides a unified layer of control over workloads distributed across hyperscalers, or on-premise datacenters. This prevents security inconsistencies between platforms and provides visibility into hidden dependencies between distributed services, optimizing both protection and architecture.
In ransomware containment scenarios, microsegmentation is critical. If a server is compromised, the attack is isolated because it cannot spread to other systems or to backups. The impact is drastically reduced, and recovery is much faster.

From banking to healthcare and manufacturing, microsegmentation keeps critical environments safe and stops a breach from snowballing into a crisis.

Microsegmentation as a strategic investment

Beyond its role as a security control, microsegmentation is consolidating as a strategic investment for organizations aiming to strengthen their digital capabilities. It reinforces business continuity, enables agile adaptation to regulatory requirements, and fosters trust in an increasingly distributed and complex environment.

Microsegmentation isn’t just a technical safeguard, it’s a strategic investment aligned with Zero Trust and business continuity.

This approach naturally aligns with Zero Trust principles, by establishing granular controls that ensure no communication or traffic flow is trusted without prior verification. Its implementation makes it possible to stop lateral movement within the network, block attacks before they escalate, and act proactively against increasingly sophisticated threats such as ransomware.

■ Microsegmentation is not a passing trend but a structural component of infrastructure and application cyber resilience. At Telefónica Tech, we accompany companies on this journey with solutions that turn security into a sustainable competitive advantage and reinforce digital trust in the long term. Learn more →