Compared: Microsoft Defender EASM
Microsoft Defender EASM vs. Attack Surface Scan
Microsoft Defender External Attack Surface Management (Defender EASM) is a large-scale discovery platform billed per asset through Azure. Attack Surface Scan monitors the domains you prove you own at a flat monthly price. Both find forgotten systems, rank known vulnerabilities and map findings to compliance frameworks. This page is the honest version of how they differ, including where Microsoft is ahead.
No card required to start. Plans from $25/month, flat. Microsoft Defender EASM facts checked September 2026.
The short version
Choose Defender EASM if
You need to find assets you do not know you own, across a large estate, starting from your company name, network ranges and registration records; you already run Microsoft Sentinel or Security Copilot; and a bill that tracks your asset count suits how you budget.
Choose Attack Surface Scan if
You know your domains and want everything under them watched, with a flat price procurement can approve once, alerts in Slack, Teams, PagerDuty or Jira, an audit evidence pack, and no Azure subscription. MSPs get white-label reports and client workspaces.
What is the same
Discovery of forgotten systems, known vulnerabilities including "potential" matches when a version is hidden, a view of what attackers are actively exploiting, certificate and domain expiry, registrar lock checks, website privacy checks and OWASP, CWE and GDPR views.
Side by side
Microsoft Defender EASM's column is from its public documentation and product pages, listed at the foot of this page. "Not listed" means we could not find the capability described there, not that it is proven absent. Our column is the product as it ships today; the technical detail behind it is in the checks reference and the documentation.
| Capability | Microsoft Defender EASM | Attack Surface Scan |
|---|---|---|
| Finding what you own | ||
| Discovery from company name, network ranges and registration records | Yes starting points include domains, network address blocks, network operators, registration records and contact emails | No starts from domains you verify |
| Ready-made starting inventory | Yes search for your organization's pre-built attack surface | No add a domain; first report in minutes |
| Automatic discovery of new systems under your domains | Yes recurring discovery groups | Yes new certificates within about 15 minutes, plus nightly discovery |
| Scanning of whole network ranges you own | Yes checks the open services on every address in the network ranges you own | No systems under your verified domains only |
| Only checks what you have proven you own | Partial strongly connected assets are approved automatically; weaker ones wait for review | Yes nothing is checked before ownership is proven |
| Inventory with hosting context and change history | Yes inventory changes dashboard, 7 or 30 days | Yes with where each system is hosted and who removed what |
| Risk and prioritisation | ||
| Known vulnerabilities in detected software | Yes including "Potential" insights when a version is hidden | Yes including potential matches, narrowly scoped |
| Priority for vulnerabilities attackers are exploiting | Yes CISA known exploits dashboard | Yes government exploited list plus exploitation-likelihood scores |
| Exposed services | Yes sensitive services and open ports charts | Yes more than 120 service types |
| Reputation of your addresses | Yes Microsoft's own data plus external sources | Yes public abuse feeds |
| Certificate and domain expiry, weak certificates | Yes | Yes plus an early warning when automatic renewal has stalled |
| Alert within minutes when a certificate is issued in your name | Not listed | Yes about 15 minutes, with a queue for unexpected providers |
| Registrar lock checks | Yes domain configuration chart | Yes plus an alert when a lock is removed |
| Email spoofing protection checks | Not listed | Yes |
| Lookalike and typosquat domains | Not listed | Yes Growth and above |
| Website privacy (unencrypted forms, cookies) | Yes GDPR compliance dashboard | Yes |
| Reporting and compliance | ||
| OWASP Top 10, CWE, CISA exploited and GDPR views | Yes eight dashboards, including CWE Top 25 | Yes |
| PCI DSS and CIS Controls views | Not listed | Yes |
| Dated evidence pack for auditors and insurers | Not listed chart data exports to CSV | Yes branded PDF showing monitoring ran all period |
| Spreadsheet export | Yes per chart segment | Yes findings, inventory and changes |
| Integrations, access and buying | ||
| Security data platform | Yes data connections to Log Analytics and Azure Data Explorer, for Microsoft Sentinel | Partial any security tool that accepts a standard-format webhook |
| Alerts to Slack, Microsoft Teams, PagerDuty and Jira | Not listed | Yes every plan |
| AI assistant | Yes Microsoft Security Copilot | Yes Claude, ChatGPT, Cursor and other assistants |
| Managing many client organizations | No no cross-tenant access, including through Azure Lighthouse | Yes client workspaces, per-client alerts, white-label reports |
| What you need to start | Partial an Azure subscription | Yes an email address |
| Trial | Yes 30 days per resource | Yes 7 days, no card |
| Pricing | Partial $0.011 per billable asset per day | Yes flat per plan, from $25 a month |
Where Defender EASM is stronger
Said plainly, because a comparison that only lists wins is an advert.
Finding what you do not know you own
Discovery starts from your company name, network ranges, registration records and contacts, and follows connections outward. For a large group with subsidiaries and acquisitions, that finds infrastructure a domain-led tool never will.
Scanning whole network ranges
Microsoft scans the open ports across the addresses you own, not just the systems behind your domain names. If you hold your own address blocks, that coverage matters.
Inside the Microsoft stack
Data flows to Log Analytics, Azure Data Explorer and Microsoft Sentinel, Security Copilot can answer questions about it, and it is a data source for Microsoft Security Exposure Management. Billing lands on the Azure invoice you already approve.
Very small estates on price alone
At the list rate, 30 billable assets cost about $9.90 a month, less than our entry plan. The two meet at roughly 75 assets ($25 divided by $0.33).
Where Attack Surface Scan is stronger
A price that does not move
One flat monthly price per plan, no per-asset metering and no overage charges, so discovery finding more of your estate never changes the bill. No Azure subscription and no sales cycle.
Only what you prove you own
Nothing is checked until ownership is proven, and related domains wait for you to verify them. You never pay for, or scan, infrastructure that turned out to belong to someone else.
Faster on certificates and impersonation
New certificates issued in your name are seen within about 15 minutes with a queue for unexpected providers, stalled renewals are caught weeks early, and email spoofing protection and lookalike domains are watched.
Built for MSPs and for auditors
Client workspaces, per-client alert routing and white-label reports, where Defender EASM needs a sign-in per client tenant. A dated evidence pack with PCI DSS and CIS Controls views alongside OWASP, CWE and GDPR.
Every Attack Surface Scan check is read-only and runs only against domains whose owner has proven control (see how scanning works). Nothing is installed. We do not scan whole network ranges, test whether a weakness can actually be exploited, monitor criminal forums, or connect to your cloud accounts.
What it costs
Microsoft publishes one rate: $0.011 per billable asset per day in US regions, about $0.33 per asset per month, after a 30-day trial on each new resource. Only approved assets are billed, but a single website behind a content network can count several times, and the count moves as discovery finds more. Our plans are flat.
| Example estate | Billable assets | Defender EASM per month (list) | Attack Surface Scan per month |
|---|---|---|---|
| A single website and a few services | 30 | 30 × $0.011 × 30 = $9.90 | Starter: $25 (up to 1 domains, 20 systems each) |
| Small business, a few domains | 300 | 300 × $0.011 × 30 = $99 | Growth: $49 (up to 5 domains, 100 systems each) |
| Mid-size company, several brands | 2,000 | 2,000 × $0.011 × 30 = $660 | MSP: $149 (up to 25 domains, 250 systems each) |
| Large enterprise with subsidiaries | 10,000 | 10,000 × $0.011 × 30 = $3,300 | Enterprise: by quote |
Arithmetic on Microsoft's list price, 30-day month, not a quote: enterprise agreements can carry discounts, and a Defender EASM "asset" (an approved host and address pair, address or domain) is not the same unit as our "system", so read the rows as orders of magnitude. Our column assumes the estate fits the plan's domain and system limits. The full breakdown of what Microsoft counts as billable is in our Defender EASM pricing guide.
Questions people ask
Is this comparison fair to Microsoft?
That is the intent. Defender EASM is a capable platform with a much larger discovery reach than ours, and every row where it is ahead is marked as such. Facts come from Microsoft Learn and the Azure price list, linked at the foot of this page and checked in September 2026.
How much does Microsoft Defender EASM cost?
The list rate is $0.011 per billable asset per day in US regions, about $0.33 per asset per month, after a 30-day free trial on each new resource. Attack Surface Scan is a flat $25, $49 or $149 a month by plan, with Enterprise by quote.
Is Defender EASM being retired?
We found no retirement announcement as of September 2026. Microsoft's documentation was updated in 2026 and the product is a data source for Microsoft Security Exposure Management. Check Microsoft's documentation before signing a long commitment.
Do I need Azure to use Attack Surface Scan?
No. You sign up with an email address, prove you own a domain and the first report is ready in minutes. There is nothing to install and no cloud subscription to set up.
Can we use both?
Yes. Some teams use Defender EASM for broad discovery across a large group and Attack Surface Scan for day-to-day monitoring of the domains that matter most: fast certificate alerts, email spoofing and lookalike watch, alerts in Slack or Teams, and the evidence pack for auditors.
Sources
Last reviewed September 2026. Microsoft Defender EASM is a trademark of its owner, named here only to compare products; Attack Surface Scan is not affiliated with or endorsed by it. Something wrong or out of date? Tell us and we will correct it.
- Microsoft Learn: Defender EASM overview
- Microsoft Learn: What is discovery?
- Microsoft Learn: Understand dashboards in Defender EASM
- Microsoft Learn: Understand billable assets in Defender EASM
- Microsoft Learn: Defender EASM data connections
- Microsoft Learn: Microsoft Security Copilot in Defender EASM
- Microsoft Learn: External Attack Surface Management initiative in Exposure Management
- Azure Retail Prices API: Defender External Attack Surface Management meters
- Attack Surface Scan pricing
Flat price, first report in minutes.
Verify a domain and see everything under it, without an Azure subscription or a per-asset bill.
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