External Attack Surface Management (EASM)
External Attack Surface Management is the practice of continuously discovering and monitoring internet-facing assets and exposures that attackers can see from outside the organization.
What Is EASM?
EASM focuses on the public side of an organization's digital footprint, including domains, subdomains, certificates, cloud assets, exposed services, and shadow IT. The goal is to reduce unknown exposure and improve the speed of remediation for externally reachable risk.
What EASM Helps Identify
- Unknown Internet-Facing Assets: Systems that are publicly reachable but poorly tracked
- Misconfigurations: Weak settings on cloud, SaaS, or perimeter services
- Exposure Drift: Changes that create new risk after deployments or acquisitions
- Third-Party Visibility Issues: External assets tied to partners or subsidiaries
Why It Matters
Attackers often begin with what they can observe from the internet. EASM helps organizations reduce blind spots and shrink the set of opportunities available for initial access.
How FourCore ATTACK Relates
FourCore ATTACK complements EASM by validating whether discovered exposure can be turned into meaningful attack progress and whether current controls detect or interrupt that activity.
