EASM Guide Hero
 minute read

The SOC Team’s Guide to External Attack Surface Management

Get an in-depth understanding of what External Attack Surface Management is, how to implement it, and why it’s an essential element of a broader external cybersecurity program.

Why You Need This Guide

External Attack Surface Management (EASM) is a hot topic with a lot of mixed messages. Understandably, lots of questions arise when learning about EASM:

  • How is it different from attack surface management (ASM) or vulnerability management?
  • How does it work with other cybersecurity components? 
  • Do I really need it, or is it just a fad?

Let’s address this first: EASM is not a fad - it’s an essential component of a broader external cyber program. It’s a vital measure in the important work SOC teams are doing to outsmart their adversaries and protect their organizations. And you, as a cybersecurity leader, should have all the information you need - down to the fundamentals - to understand how EASM fits into the broader cyber ecosystem.

The purpose of this guide is to help you make sense of this moment. It’s to share the true value of EASM and how you can implement it within an existing program. This is the guide you need in order to not only understand EASM but advocate for it. 

What is External Attack Surface Management

At its core, EASM encompasses the comprehensive and proactive management of an organization's external digital footprint. This includes technical infrastructure, such as SaaS, security certificates, and software, and can also include broader digital realms, such as social media, online platforms, and any internet-facing entity that could impact the organization's security posture. 

In an era when digital presence is as significant as physical presence, knowing what’s exposed on the internet and related to an organization is vital. The integration of EASM with other cybersecurity solutions enhances the overall effectiveness of an organization’s defensive functions, offering a more nuanced and comprehensive approach to external risk management. 

EASM is a key player in a multilayered defense strategy, ensuring that all external aspects of an organization's digital identity are securely managed and protected against potential cyber threats.

Taking a Cyber Criminal’s POV

EASM distinguishes itself by offering a perspective that aligns closely with how adversaries view an organization’s digital presence. It’s not just about cataloging assets; it's about gaining deep visibility into how these assets are exposed and potentially perceived by malicious actors. This approach simulates the reconnaissance tactics used by adversaries, uncovering aspects of the digital footprint that might be overlooked by conventional security methods. 

By adopting the viewpoint of potential attackers, EASM provides insights into the most likely vectors for cyber attacks, allowing organizations to anticipate, prioritize, and counteract threats more effectively. This level of visibility into external exposure is crucial for a comprehensive security posture, as it reveals the real-world risks in a way that traditional asset inventory cannot; most asset inventory methods lack automation and require employee due diligence, leaving the information stale. 

Why EASM Matters in Today’s Environment

With the exponential growth in digital transformations and the expanding digital footprints of organizations, including shadow IT, there’s an opaque, complex, and unmanaged level of risk in an organization’s attack surface. 

EASM plays a pivotal role in clearing this fog by enhancing other security functions within an organization, in addition to providing benefits like: 

  1. Immediate Time to Value
    Simple onboarding with rapid configuration to achieve value at machine speed
  2. Knowing Your External Weaknesses
    Visualizing your exposures across internet infrastructure and external platforms that legacy solutions cannot see.
  3. Retaking the Advantage
    Prioritizing risk by organizing all external-facing assets by risk level and exposure type and correlating to known vulnerabilities.
  4. Gaining Operational Assurance
    Automating ongoing discovery, monitoring, and protection to achieve better decision-making and prioritization on the most critical, time-sensitive exposures.

EASM as an Enhancement to Broader External Security Programs

The practical applications of EASM extend across a range of scenarios, reflecting the  critical role it will play in modern cybersecurity strategies. For instance: 

  • EASM will be valuable in assessing third-party vendor compliance, ensuring that external partners uphold the necessary security standards to protect against supply chain vulnerabilities. 
  • It will play a pivotal role in continuous monitoring for unexpected changes or exposures in digital assets, a key measure in preventing data breaches and cyber-espionage. 
  • It will be adept at augmenting DRPS in detecting and managing instances of brand impersonation or fraudulent use across digital platforms, including social media, which is increasingly important for thwarting sophisticated phishing schemes. 
  • In the oversight of digital mergers and acquisitions, EASM will help in evaluating the digital risk profile of potential acquisitions, ensuring that new integrations do not introduce unforeseen vulnerabilities.

These examples underscore the comprehensive capabilities EASM can provide, moving beyond traditional asset inventory to offer a dynamic, real-time perspective on an organization's external digital threats. 

Gartner Agrees: EASM is the Top Cybersecurity Trend

Gartner recently identified external attack surface management as the top cybersecurity trend in the next five to 10 years. And, from the information shared thus far, it’s no surprise why. Attack surfaces are expanding and risks associated with them are becoming more complex and harder to control. According to Gartner: 

“Organizations must look beyond traditional approaches to security monitoring, detection and response to manage a wider set of security exposures.”

Their recommendation? Combining the powers of digital risk protection services and external attack surface management technology, among other core cybersecurity components, to support the visibility of business systems and identification of security coverage gaps. 

How EASM Differs From and Works With Other Core Components of Cybersecurity 

Attack Surface Management (ASM): A broad approach to identifying and managing all potential entry points for cyber threats in an organization's network.

External Attack Surface Management (EASM): Focused on identifying and mitigating risks associated with external digital assets and presence.

Vulnerability Management (VM): Concentrates on identifying, classifying, prioritizing, and mitigating known software vulnerabilities within an organization.

Digital Risk Protection (DRP): The process of protecting against threats that arise from digital channels and online interactions, ensuring the security and integrity of digital operations. This involves monitoring digital activities and trends, and managing digital risks, crucial for preserving the digital well-being of an organization. 

Cyber Threat Intelligence (CTI): A critical component of a comprehensive external cybersecurity solution, focusing on the collection, analysis, and dissemination of information about current and potential threats.


In cybersecurity, ASM, EASM, and VM are often talked about together. While each plays a vital role, they are distinct in their disciplines and uses. 

ASM covers a wide spectrum, focusing on identifying and managing potential entry points for cyber threats within an organization’s network, encompassing a variety of assets and risks. 

EASM, on the other hand, is specifically concentrated on the organization’s external digital presence, such as public-facing websites and online platforms. It is dedicated to understanding and managing risks presented by digital assets visible from outside the organization's network. 

VM, significantly different from EASM, deals with identifying, prioritizing, and remediating known software vulnerabilities. It’s a crucial discipline that addresses specific weaknesses within the organization’s software systems. 

Importantly, EASM and ASM do not replace VM. Rather, they are complementary practices. While EASM provides insights into external threats, VM ensures the internal software landscape is secure from known vulnerabilities. Together, ASM, EASM, and VM create a layered and comprehensive cybersecurity strategy, with each addressing different aspects of an organization's security posture. As an example, EASM behaves like the eyes of an adversary, learning your attack surface and discovering indicators for exploitation. While VM is a slow and vigorous method that needs to be employed selectively. 


Similar to the concepts above, EASM, DRP, and CTI are separate, yet complementary elements of a comprehensive external cybersecurity program. 

DRP plays a crucial role in safeguarding an organization's digital assets and reputation, especially during periods of extensive digital transformation. It encompasses proactive strategies and practices to secure digital assets against a myriad of risks that can emerge in the digital domain. 

CTI involves gathering data from a variety of sources to understand the tactics, techniques, and procedures of attackers. This intelligence is crucial for organizations to stay ahead of emerging threats, enabling them to update their security strategies in real time. 

When combined, EASM, DRP, and CTI form a powerful, practical framework for external cybersecurity. EASM provides a clear picture of an organization’s external exposure, identifying everything from publicly accessible systems to online brand presence. DRP then steps in, applying proactive measures to safeguard these assets from emerging digital risks. This includes monitoring for data leaks or breaches and ensuring compliance with data protection regulations. CTI complements these efforts by offering real-time intelligence about potential and active threats, informing the organization about the methods and targets of cyber attackers. 

Four Key Steps to External Attack Surface Management

An efficient, comprehensive external attack surface management solution comes down to four key components: 

  1. Discovery 
  2. Exposure identification
  3. Validation
  4. Actionable next steps 

Download the full guide to learn more.

How EASM Helps Protect Against Advanced and Sophisticated Threats

EASM significantly enhances the capabilities of various cybersecurity business units by providing critical visibility and exposure identification. For instance, in the realm of VM, EASM's detailed insights into the organization's external digital assets allow VM teams to better prioritize their efforts. With EASM's comprehensive mapping of the external digital presence, VM can focus on securing the most exposed and vulnerable assets, thereby optimizing the allocation of resources and improving overall security effectiveness.

Another area where EASM proves invaluable is in enhancing cybersecurity incident response teams. EASM's ability to continuously monitor and identify changes or new exposures in the external digital environment means that incident response teams can react more quickly and effectively to external threats. By having a clear picture of the organization's external attack surface, these teams can anticipate potential attack vectors and prepare more targeted response strategies, significantly improving the organization’s ability to mitigate and respond to cyber incidents.

An Essential Component to an External Cybersecurity Protection Program

Integrating external attack surface management into existing cybersecurity programs offers a unique, adversarial perspective. This integration allows for unparalleled visibility into the organization’s external digital presence, mirroring the view that potential attackers might have. 

By providing a clear picture of what is exposed to the outside world, EASM enables organizations to see their digital assets through the eyes of an adversary. This visibility is crucial in identifying the most vulnerable and exposed areas that could be potential targets for attack. It allows cybersecurity teams to anticipate where attacks are most likely to occur and to take preemptive measures to fortify these areas.

It’s not an exaggeration to say that EASM transforms the way organizations perceive and respond to external threats, making it an indispensable tool for maintaining robust and proactive external cybersecurity defenses.

The Future of EASM

As we look to the future, the role of external attack surface management in cybersecurity is poised to expand and adapt to the changing digital landscape. The evolution of EASM will be marked by a deeper integration with technologies, such as artificial intelligence and advanced analytics. These technological advancements will further enhance EASM’s predictive capabilities, allowing for more sophisticated, automated, and real-time monitoring and analysis of external threats. 

As digital ecosystems evolve, EASM will adapt to cover a wider range of digital assets and platforms, ensuring comprehensive protection. This progression will position EASM not only as a defensive tool against external threats but also as a strategic component in shaping and securing an organization's broader digital strategy. EASM's evolution signifies a move towards a more dynamic, adaptive approach in cybersecurity, crucial for safeguarding organizations in a rapidly evolving external, digital world.

Download the full guide to learn more.

Keep Learning

See and secure critical external assets

The industry's leading digital risk protection, now with robust External Attack Surface Management. Complement ZeroFox’s industry-leading digital risk protection to discover, analyze, and prioritize remediation for vulnerabilities across your most critical internet-facing assets.

ESG Report: The Intersection of ASM, Cyber-Threat Intelligence, and DRP

Read the in-depth research from TechTarget’s Enterprise Strategy Group on how organizations are evolving their approach to attack surface management, cyber-threat intelligence, and digital risk protection.

ESG Report: The Intersection of ASM, Cyber-Threat Intelligence, and DRP

Forrester has recognized ZeroFox as a leader in Digital Risk Protection with best-in-class takedown services.

Read this Forrester Total Economic Impact study to see how ZeroFox delivers a 267% Return on Investment.

Forrester has recognized ZeroFox as a <span class="text-fox-red">leader in Digital Risk Protection</span> with best-in-class takedown services.

More popular resources