Guide · EASM

What is EASM? A simple guide for SMEs

Artifhack · July 2026 · 5 min read

Your company has a website. Probably also email, a VPN, a customer portal, an old test site nobody shut down and a few cloud services opened by a provider. All of this is visible from the Internet — and therefore visible to an attacker. Together, these elements make up your external attack surface.

EASM: a one-sentence definition

The termEASM (External Attack Surface Management) means continuously discovering, inventorying and monitoring everything your company exposes on the Internet, from an attacker's perspective — from the outside, without installing anything on your machines.

Why does this matter for SMEs?

Attackers' tools constantly scan the Internet and target poorly secured systems, regardless of company size. Your attack surface also grows on its own:

Shadow IT : a test server, a SaaS tool opened by an employee or a subdomain forgotten after a project.
Service providers : web agencies, managed service providers and integrators create access points and environments you may not always see.
Time : a service that was secure in 2023 may be vulnerable in 2026 if nobody has updated it.

The key point: you cannot protect assets you do not know you own. Most companies discover 20–30% of exposed assets they did not know existed during their first external inventory.

What does an EASM tool actually do?

Discovery — starting with your domain name, it finds your subdomains, IP addresses, exposed services, certificates and technologies.
Inventory — it classifies these assets and detects problems: unnecessary open ports, outdated versions, expired certificates and accessible sensitive files.
Continuous monitoring — it rescans regularly and alerts you when something new appears or changes.

EASM alone is not enough: why correlation matters

An open port is not necessarily serious. Neither is a leaked password on its own. Together, they can be : that is an attack path. Artifhack combines external exposure with data leak detection and breach intelligence to produce a correlation score : instead of 400 alerts, you see the 3 scenarios an attacker would actually exploit, in priority order.

Where should you start?

List what you think you expose (websites, email, VPN, business tools).
Run an initial external scan to compare that list with reality.
Close or update anything that does not need to be exposed.
Set up continuous monitoring: your attack surface changes every week.

See your attack surface in a demo

Further reading: ANSSI's IT security hygiene recommendations (cyber.gouv.fr) · IBM “Cost of a Data Breach” report.