MSSP vs MDR: Which Security Service Fits Your Business?

You’ve decided your business can’t run security alone. Good call. Now you’re comparing proposals, and one says “MSSP” while another says “MDR.” Both promise 24/7 monitoring. Both mention a security operations center. Both cost real money every month.

The difference matters most at the worst possible moment: when an attacker is inside your network at 2 a.m. One provider may send you an email. The other may isolate the infected laptop before you wake up.

This guide explains what each service covers, who takes action during an incident and what to ask before you sign anything.

The short difference

A managed security service provider (MSSP) runs and maintains security for you across a broad scope. Think firewalls, VPNs, email filtering, vulnerability scans, log monitoring and compliance reporting. Its job is breadth: keep the security stack configured, updated and watched.

A managed detection and response (MDR) provider does one thing in depth: find and stop active threats. Its analysts watch alerts from endpoint, identity, cloud and network tools, hunt for attackers who slipped past defenses, and take containment actions when something is real.

Key takeaway: An MSSP mainly manages and monitors. An MDR provider mainly investigates and responds. If your contract doesn’t say who isolates a compromised device, assume nobody will.

The labels aren’t regulated, and the lines have blurred. Many MSSPs now sell MDR tiers, and some MDR providers manage firewalls. Judge each provider by the actions in its contract, not by the acronym on its website.

Where response responsibility sits

This is the most important difference, so it gets its own section.

When an alert fires, there are 4 possible stages:

1. Detect. A tool raises an alert.
2. Triage. Someone decides whether it’s real or a false positive.
3. Contain. Someone takes action to stop the spread, such as isolating a device, disabling an account or blocking an IP address.
4. Recover. Someone removes the attacker, restores systems and fixes the root cause.

Traditional MSSP monitoring often covers stages 1 and 2, then hands stage 3 back to you or your IT provider with a ticket or a phone call. MDR services are built around stage 3, with analysts allowed to act directly in your tools. Stage 4, full recovery, is frequently a separate incident response engagement for both.

CISA’s joint advisory on protecting managed service providers and their customers, published with NSA, FBI and international partners in May 2022, makes the same point. It tells customers to make sure contracts specify whether the provider or the customer owns responsibilities such as hardening, detection and incident response. It also recommends that contracts require notification of confirmed or suspected security events, and that the most important logs be kept for at least 6 months, since incidents can take months to discover.

What each service usually covers

Every provider packages things differently, so use this as a checklist, not a guarantee.

Typical MSSP services:

• Firewall, VPN and intrusion prevention management
• Email and web filtering
• Log collection and SIEM monitoring
• Vulnerability scanning and patch reporting
• Security device updates and configuration changes
• Compliance reports for audits and customers

Typical MDR services:

• 24/7 monitoring of EDR or XDR alerts
• Investigation of each real alert, with a written summary
• Active containment, such as host isolation and account lockout
• Proactive threat hunting across your environment
• Guidance on remediation after an incident

If you’re unsure what EDR and XDR mean in this context, our guide to XDR vs EDR vs MDR explains the tools, and what SIEM is covers the log side MSSPs often run.

How pricing works

Pricing varies widely by provider, company size and scope, so compare quotes line by line rather than by the headline number.

Ask every provider for a list of what’s not included. Onboarding fees, after-hours remediation, forensics and extra log retention are common add-ons. For broader budgeting, see how much cybersecurity costs for a small business.

Questions to ask providers

Bring these questions to every sales call and ask for the answers in writing.

Scope and response 1. Which actions can your analysts take without calling us first? Can you isolate devices, disable accounts and block IPs? 2. What is your guaranteed time to notify us of a confirmed incident, and how is it measured? 3. What happens after containment? Is recovery included, billed hourly or a separate contract? 4. Do you hunt for threats proactively, or only respond to alerts?

People and coverage 5. Is your security operations center staffed 24/7/365, by your own employees or a subcontractor? 6. Who will we talk to during an incident, and how do we reach them?

Data and access 7. Which tools and data sources do you need access to, and how is that access secured? 8. How long do you keep our logs, and can we export them if we leave? 9. Do you require multi-factor authentication on every account your staff use to reach our systems?

Proof and fit 10. Can you show a sample incident report and a sample monthly report? 11. Do you support our compliance needs, such as reports our auditors or customers request? 12. How do you offboard us and remove your access at the end of the contract?

Questions 7 and 9 echo CISA’s advice. Its advisory recommends that contracts require MFA on all provider accounts that access customer environments, and it flags that provider accounts are often left active after a contract ends.

Compliance still sits with you

Outsourcing security doesn’t outsource accountability. CISA’s risk guidance for managed service customers says plainly that outsourcing IT management doesn’t absolve an organization of its risk management responsibilities, and it suggests defining vendor, customer and shared duties in the agreement. If your business handles customer financial information and falls under the FTC’s Safeguards Rule, the FTC says your designated Qualified Individual can work for a service provider, but your company must still oversee that person and the provider’s work. The FTC’s guidance also says your contracts should spell out security expectations and build in ways to monitor the provider. Our FTC Safeguards Rule guide has the details. This is not legal advice.

Cyber insurers often ask similar questions about 24/7 monitoring and response. See cyber insurance requirements for what applications commonly ask.

Where to start

1. Map your gap. Write down what’s failing today. Is it unmanaged firewalls and missed patches (an MSSP gap) or nobody watching alerts at night (an MDR gap)?
2. Inventory your tools. List your endpoints, cloud apps, firewalls and existing security licenses. Providers will quote more accurately.
3. Shortlist 3 providers. Include at least one MDR specialist and one MSSP if you’re unsure which you need.
4. Run the questions above. Score each provider on response authority, coverage and transparency.
5. Read the contract for responsibilities. Make sure detection, containment, recovery and notification each have a named owner.
6. Update your incident plan. Add the provider’s contacts and escalation steps to your incident response plan.

If you already work with an IT provider, our guide on how to choose a managed IT service provider explains how an MSP, MSSP and MDR can work together without gaps. You can also compare options in our top lists.

Conclusion

MSSPs and MDR providers solve different problems. An MSSP keeps your security stack running and watched. An MDR provider hunts and stops attackers. Many businesses end up using both, or a single provider that does both. Either way, the contract should say clearly who acts, how fast and what happens after the first alert.

Sources

• CISA advisory AA22-131A: Protecting against cyber threats to managed service providers and their customers — contract responsibilities, MFA for provider accounts, log retention and notification
• CISA Insights: Risk considerations for managed service provider customers — outsourcing doesn’t remove risk responsibility; defining shared responsibilities in vendor agreements
• FTC: Safeguards Rule, what your business needs to know — Qualified Individual at a service provider and oversight duties
• Microsoft Learn: What is Microsoft Defender XDR? — example of the detection and response tooling MDR services often run on