Glossary

What is Attack Surface Management (ASM)?

Attack Surface Management is the continuous process of discovering, inventorying and securing all of an organisation’s internet-facing assets — from the attacker’s point of view.

Definition

Attack Surface Management, defined

Attack Surface Management (ASM) is the ongoing discovery, inventory, classification and monitoring of every asset your organisation exposes to the internet — domains, IP addresses, cloud services, APIs, applications and more. Unlike traditional vulnerability scanning, which checks a known list of assets, ASM starts from the outside and finds the assets you don’t know about, then continuously assesses them for exposures. It answers two questions: “what do we have exposed?” and “what’s wrong with it?”

External Attack Surface Management (EASM) is the subset of ASM focused specifically on internet-facing assets — the part an attacker can actually reach.

Why it matters

You can’t secure what you can’t see

Cloud, acquisitions, third parties and shadow IT mean new internet-facing assets appear constantly. Research suggests organisations are aware of only around two-thirds of their real external footprint — the rest is exactly where attackers look first.

Components

What’s in your attack surface

Domains & subdomains

Every domain and subdomain tied to your organisation — including marketing microsites, staging environments and domains spun up by teams outside central IT.

IP addresses & ranges

Owned and associated IP ranges across providers and regions, including cloud-assigned addresses that change as infrastructure scales up and down.

Cloud assets

Public-facing resources across AWS, Azure and Google Cloud — storage buckets, instances, databases and serverless endpoints reachable from the internet.

APIs

Known and unknown API endpoints exposed externally, including undocumented, legacy and shadow APIs that connect straight to your data and logic.

Web applications

Public web apps, customer portals and login pages — each a potential entry point if left unpatched, misconfigured or forgotten.

SSL/TLS certificates

Certificates across your estate, including expiring, weak or misconfigured TLS that erodes trust, breaks services or signals neglected infrastructure.

Exposed services

Open ports, databases, remote-access and admin interfaces that should never be reachable from the public internet but often are.

Shadow IT

Unmanaged infrastructure and forgotten assets — stood up by teams outside IT or inherited through mergers and acquisitions, invisible to traditional inventories.

How it works

The ASM lifecycle

01

Discover

Starting from a single seed such as a domain, map your complete internet-facing footprint — domains, IPs, cloud, APIs and certificates — including unknown and shadow assets, with no agents to deploy.

02

Analyse

Assess every discovered asset for vulnerabilities, misconfigurations, exposed services and policy violations, enriching each finding with up-to-date threat intelligence.

03

Prioritise

Cut through the noise with risk-based scoring that weighs exploitability, exposure and business context, so your team fixes the issues that genuinely matter first.

04

Monitor

Continuously re-discover and re-assess as your environment changes, so new assets and exposures are caught within hours — not at your next quarterly scan.

FAQ

Attack Surface Management FAQ

What is the difference between ASM and vulnerability management?

Vulnerability management assesses a known list of assets. ASM first discovers what you have — including unknown and shadow assets — then continuously assesses them. ASM answers “what is exposed?” before “what is wrong with it?”

What is the difference between ASM and EASM?

EASM is the part of ASM focused on internet-facing (external) assets — what an attacker can reach from outside your network.

Does ASM require agents?

No. ASM is performed externally from the attacker’s perspective, so there are no agents to deploy.

How often should the attack surface be scanned?

Continuously. The attack surface changes daily, so point-in-time scans quickly go stale.

See your attack surface

Get the attacker’s view of your external footprint with Attack Insights.

External Attack Surface

Discover and monitor every internet-facing asset you own.

Detect new CVEs and exposures as they appear.

Find misconfigurations across AWS, Azure and GCP.

Prove your security controls actually work.

Threat & Digital Risk

Our public threat intelligence platform, in real time.

Spot leaked credentials and targeted threats early.

AI-driven prioritisation that cuts through the noise.

Protect your brand, data and people beyond the perimeter.

API & Email Security

Discover and test externally exposed APIs.

Stop spoofing with SPF, DKIM and DMARC checks.

Dashboards and board-ready security reporting.

Continuously test your public web applications.

Stream validated findings to your SIEM, SOAR and ticketing tools.

Explore

See the full Attack Insights platform.

See Attack Insights in action.