How is EASM different from a penetration test or vulnerability scan?

A pen test is a point-in-time assessment of known assets. EASM continuously discovers unknown and changing assets — new subdomains, forgotten buckets, expiring certificates — and diffs each scan against the last, so discovery is an ongoing feed rather than a project.

EASM guide for MSPs: external attack surface management

Q: What is External Attack Surface Management (EASM)?

EASM is the continuous discovery, inventory, and monitoring of everything an organization exposes to the internet — domains, subdomains, IPs, open ports, certificates, cloud services, and third-party scripts. Unlike a one-time pen test, it assumes the surface is always changing and watches it continuously.

What External Attack Surface Management is, why it matters for MSPs, and how to operationalize continuous discovery across every client.

What EASM is

External Attack Surface Management is the continuous discovery, inventory and monitoring of everything an organization exposes to the internet — domains, subdomains, IPs, open ports, certificates, cloud services and third-party scripts.

Unlike a one-time pen test, EASM assumes the surface is always changing and watches it continuously.

Why MSPs need it

MSPs manage dozens of client environments, each with shadow IT and forgotten assets. A single dangling subdomain or public bucket can become a breach. EASM gives you portfolio-wide visibility without installing anything.

What to monitor

Subdomains (alive / offline / dangling), open and risky ports, SSL/TLS health, email authentication (SPF/DKIM/DMARC), technology stack and end-of-life software, and third-party exposure.

How continuous discovery works

SBCMSP enumerates each client’s footprint on a schedule, diffs it against the last scan, and alerts on new or changed assets — so discovery is a feed, not a project.

Operationalizing EASM

Wire findings into your remediation workflow with SLAs, route them to your PSA as tickets, and report posture to clients under your brand. Discovery only matters if it drives action.

Frequently asked questions

What is External Attack Surface Management?
The continuous discovery, inventory, and monitoring of everything an organization exposes to the internet — domains, subdomains, IPs, open ports, certificates, cloud services, and third-party scripts.

How is EASM different from a pen test or vulnerability scan?
A pen test is a point-in-time assessment of known assets. EASM continuously discovers unknown and changing assets and diffs each scan against the last, so discovery is an ongoing feed rather than a project.

Why do MSPs specifically need EASM?
MSPs manage dozens of client environments, each with shadow IT and forgotten assets. A single dangling subdomain or public bucket can become a breach. EASM gives portfolio-wide, agentless visibility from one console.

What should EASM monitor?
Subdomains (alive, offline, or dangling), open and risky ports, SSL/TLS health, email authentication (SPF/DKIM/DMARC), technology stack and end-of-life software, and third-party exposure.

External Attack Surface Management (EASM): the complete guide for MSPs