MDR: Managed Detection and Response

Reviewed by Marcus Chen, CISSP

MDR services provide 24/7 threat detection and response for $15 to $50 per endpoint per month, making professional security monitoring accessible to organizations that cannot justify a $1.5 to $3 million annual investment in an in-house SOC. However, MDR quality varies dramatically across the market, and the 2023 Ponemon Institute found that 37% of organizations using MDR were dissatisfied with response times or detection accuracy. Evaluating analyst-to-customer ratios, response SLAs, and whether the vendor performs actual remediation separates valuable services from expensive alert forwarding.

MDR services outsource threat detection and response to a vendor. Instead of building and staffing a security operations center in-house, you pay a per-endpoint fee and a vendor runs detection tools and maintains a team of analysts to investigate alerts and advise on response. This model is attractive for organizations that can't afford building a SOC but need threat monitoring. But MDR services vary dramatically in quality and capability, and the marketing often doesn't match the reality of what you actually get. Understanding what MDR includes, what quality to expect, and what to evaluate will help you choose a service that provides value rather than just checking a compliance box.

MDR bundles three main components together. First is an endpoint detection and response tool, usually an EDR agent that runs on computers and servers and monitors system activity for suspicious patterns. Second is a threat intelligence layer—the vendor uses threat research and known attack patterns to create detection rules that identify malicious activity. Third is a human team: analysts employed by the MDR vendor who investigate alerts, determine whether they're real threats, advise on response, and sometimes execute response actions directly in your environment.

The promise is appealing. You get continuous monitoring and response capability without building and maintaining a SOC in-house. The vendor handles tool updates, rule tuning, analyst staffing, and training. You pay a per-endpoint or per-user fee and the vendor handles the complexity. For organizations that can't justify a full-time security analyst on staff, MDR is often the most practical way to have professional threat monitoring. But the quality of that monitoring depends heavily on the vendor's capabilities and expertise, and quality varies significantly across the market.

What MDR Detection Actually Covers

MDR detection centers on endpoint agents that monitor system behavior and send telemetry to the vendor's cloud platform for analysis against known attack patterns. that monitor system behavior. These agents watch what's happening on your computers and servers—what processes are running, what files are being accessed, what network connections are being made, what registry changes are happening on Windows systems. The agents send this data to the MDR vendor's cloud platform where detection rules analyze it looking for malicious activity.

The quality of detection depends on the quality of the vendor's threat intelligence and rule library. A vendor with sophisticated threat research will have detection rules based on actual attack patterns they've observed. A vendor with less mature threat intelligence will have more generic rules. Some vendors create custom detections for their customers based on that customer's specific risk profile. Others use one-size-fits-all detections that might not align with what your organization is most likely to face.

An important distinction is what the agents actually monitor and what that means for your systems. Some endpoint agents are comprehensive—they capture lots of data about system activity, which gives the SOC analysts better visibility but also creates performance overhead on the systems running the agents. A heavily loaded agent might slow down systems. Other agents are more focused and efficient, monitoring specific threat types but potentially missing other threats. The tradeoff between visibility and system impact is important.

The agents also need to be able to communicate back to the vendor's platform. If your network is locked down for compliance or security reasons, agent communication might be restricted. If your systems can't reach the internet or can only reach approved destinations, you might not be able to run the vendor's standard agent. Some organizations work around this by running agents on a subset of critical systems or by running them in offline mode that uploads data periodically rather than real-time. These workarounds affect detection latency—how quickly threats are detected after they happen.

Coverage is another consideration. MDR is typically priced per-endpoint, so you need to cover the endpoints where threats matter most. A 500-person company might protect 600 endpoints (counting servers and workstations). But what about contractors' laptops? What about BYOD devices? What about IoT devices on the network? Coverage gaps are blind spots where threats could hide.

How MDR Response Actually Works

MDR response ranges from alert notification to full hands-on remediation depending on the vendor and service tier, and the difference between these capabilities determines whether you get actual incident response or just faster email alerts.

When the MDR vendor's detection system identifies a potential threat, an analyst from the vendor's team gets involved. A good analyst will investigate: Is this a real threat or a false positive? They gather context about the activity. What system was affected? What was the suspicious activity? Are there other indicators that suggest an actual attack? Based on the investigation, they make a decision: close the alert as false positive, handle it locally, or escalate to your incident response team.

Good MDR vendors go beyond just investigating—they actively execute response. If they identify malware on a system, they might isolate the endpoint from the network so it can't communicate with command-and-control servers. They might kill malicious processes running on the system. They might roll back suspicious configuration changes. They might reset compromised credentials. This kind of proactive response requires the vendor to have access to your environment and authority to make changes.

Response quality depends on analyst expertise and understanding of your environment. An MDR analyst knows attack patterns and detection is their specialty. But they might not know your business operations. If they recommend isolating a particular system, they might not know that system is handling critical transactions right now. A good MDR vendor invests in learning their customers' environments so response recommendations are informed. A vendor that treats all customers generically might give advice that doesn't fit your situation.

The relationship between MDR response and your own incident response process matters. If you have an internal incident response team, how does the MDR vendor hand off to them? Do alerts go directly to your incident response system? Does the MDR analyst need to contact someone on your team? Is there a defined escalation procedure? Integration here determines how quickly you can move from detection to full response. Poor integration creates handoff delays where alerts sit in limbo between the MDR vendor's team and your team.

Integration With Your Existing Environment

MDR must integrate with your existing security stack, and vendors that require ripping out current EDR tools or that cannot ingest logs from your cloud and network systems will leave gaps in coverage.

MDR only works if the vendor's tools and processes fit into your existing environment. Many organizations have security tools from multiple vendors. You might have a SIEM collecting logs, EDR tools from a different vendor, email security from another vendor, and network monitoring from yet another. Adding MDR to this environment creates another integration point.

Some MDR vendors are good at integration. They can send alerts to your SIEM. They can query your other tools for context. They can pull data from multiple sources to get a complete picture of suspicious activity. Other vendors are more isolated—they only talk to their own tools and the visibility is limited to what their agents see.

Network access is also critical. The MDR vendor's agents need to be able to communicate with the vendor's cloud platform to send telemetry. The vendor's analysts need to be able to log into your systems to investigate and potentially execute response. If your network is locked down for compliance reasons, this can be problematic. Some organizations work around this by creating a security exception for the MDR vendor's traffic. Others find that the restrictions are incompatible with the vendor's standard way of operating.

Data flow also matters. Some vendors want to collect everything—full system telemetry, complete process trees, network connection details. This provides maximum visibility but can create bandwidth and storage issues. Other vendors collect a subset of data and ask you what they should focus on. Different vendors have different philosophies about how much data collection is appropriate.

Comparing MDR to Internal Alternatives

Building an internal SOC costs $1.5 to $3 million annually for 24/7 coverage, making MDR at $15 to $50 per endpoint per month the more practical option for organizations under 1,000 employees.

Organizations considering MDR need to understand how it compares to building an internal SOC or deploying a SIEM themselves. Each option has different tradeoffs.

MDR's main advantage is that it outsources the operational burden. You don't need to recruit analysts in a competitive talent market. You don't need to maintain infrastructure. You don't need to keep tool licenses current and updated. The vendor handles all of that. You pay a subscription, typically $20-50 per endpoint per month depending on the vendor and service level. A 600-endpoint company might pay $120K-$300K per year. This is a transparent cost.

The disadvantage of MDR is dependency on vendor quality. You're trusting the vendor's analysts to catch threats. If their detection is weak or their analysis is mediocre, you won't know until an incident happens that they missed. You also have less control over the process. The vendor's investigation procedures and escalation decisions might not match your risk tolerance. If the vendor's tool doesn't integrate well with your other security tools, you have less visibility than you should.

An internal SOC gives you complete control. You define the procedures. Analysts understand your environment. You own the data and aren't dependent on vendor availability or responsiveness. But you pay for all of it. A Tier 1 analyst costs $60K-$80K per year including benefits. You need at least two analysts for 24/7 coverage. Add infrastructure, tools, and management, and you're easily at $500K-$1M+ per year. The cost is high but for large organizations it can be cheaper per employee than MDR.

A SIEM approach puts infrastructure on you but outsources some analysis. You deploy a SIEM, collect logs from your environment, then either staff analysts in-house or use a managed SIEM service. This gives you more control over what's being monitored but requires more expertise to operate. A SIEM that's not properly tuned generates alert noise that wastes analysts' time.

For small organizations, MDR is usually the right choice. The internal SOC cost is not justified. For mid-sized organizations, MDR is often cost-competitive with internal SOC and has lower operational burden. For large organizations with sophisticated needs, internal SOC or SIEM might cost less per unit and provide better control.

Vendor Selection: What Actually Matters

Response time SLAs, analyst-to-customer ratios, and whether the vendor performs hands-on remediation are the three metrics that separate effective MDR from expensive alert forwarding.

Evaluating MDR vendors is challenging because you can't easily test the service before committing. You can run a pilot program with one or two endpoints, but that doesn't test the vendor's analyst team or response capabilities under real conditions. Several evaluation criteria matter.

Ask for references from organizations similar to yours in size and industry. Talk to them about their actual experience. Did the vendor catch real incidents? How fast was the response? How many false positives do they deal with? References from actual customers are more reliable than vendor marketing claims.

Lab testing of EDR tools gives you information about detection capabilities. Third-party testing organizations run EDR tools against known malware and attack scenarios. If a vendor's tool performs poorly in independent testing, that's a red flag. But lab testing doesn't evaluate the analyst team or response processes.

Ask specific questions about the vendor's analysts. What's the average experience level? What certifications do they have? What's the average analyst-to-endpoint ratio? A vendor with 100 analysts covering 100,000 endpoints is understaffed compared to a vendor with 100 analysts covering 20,000 endpoints. Analyst quality and capacity determine response quality.

Ask about response time. What's the average time from alert to analyst contact? What about for high-severity alerts? If the vendor is slow to respond, detection that happens quickly becomes response that happens slowly. That's not useful.

Ask about false positive rates. Does the vendor have data on what percentage of their alerts are actual threats versus false positives? If a vendor won't share this metric, they probably don't have good data. A vendor that claims near-zero false positive rate is either lying or so conservative in their detections that they're missing threats.

Ask how integration works. How do alerts get to your incident response team? Can you integrate with your SIEM? Can the vendor pull data from other security tools for context? Poor integration creates operational friction.

Pricing questions matter too. Is pricing per-endpoint, per-socket, or something else? Are there volume discounts? What are the commitment terms? Can you reduce endpoint count if your organization shrinks? Some vendors allow quarterly adjustments. Others lock you in for a year.

When MDR Delivers Value and When It Doesn't

MDR delivers the most value to organizations between 100 and 1,000 employees that need professional monitoring but cannot justify in-house SOC staffing.

MDR provides real value for organizations that need monitoring but can't afford or don't want to staff an internal SOC. A 200-person company with limited IT security budget benefits from paying $20-30 per endpoint and getting professional monitoring. The alternative—hiring one or two analysts on staff and building SIEM infrastructure—is higher cost and higher operational burden.

MDR also provides value if you have specific threats that concern you. A company in a heavily targeted industry, or a company that's experienced incidents before, might benefit from MDR's focus on threat detection and response. The vendor's analysts are doing this every day and can recognize sophisticated attacks more reliably than an internal analyst could.

MDR provides less value if your real problem isn't detection but response. If you have good detection capability already—either through your own tools or through compliance monitoring—but you struggle with incident response, MDR might not address the core issue. MDR is detection and response bundled together. If you need response help but have adequate detection, you might benefit more from incident response consulting.

MDR also provides less value if your environment is so specialized that a generic service won't work. A healthcare organization with unique EHR systems and patient data flows might need specialized monitoring that a general-purpose MDR doesn't understand. A financial institution with proprietary trading systems might be better served by building specialized internal capabilities.

Cost comparison drives many MDR decisions. If your cost to build an internal SOC would be higher than MDR cost, MDR is the logical choice. If your organization is large enough that internal SOC cost would be lower, it might make sense to build internally. But cost shouldn't be the only factor. Complexity, risk profile, specialized needs, and control requirements matter too.

Frequently Asked Questions

How much does MDR cost?

MDR typically costs $15 to $50 per endpoint per month depending on the vendor, capabilities, and service tier. For a 500-endpoint organization, that translates to $90,000 to $300,000 annually. This is substantially less than the $1.5 to $3 million annual cost of building and staffing an internal SOC.

What is the difference between MDR and MSSP?

MDR focuses on threat detection and response with active investigation by security analysts. MSSPs (managed security service providers) offer broader IT security services including firewall management, vulnerability scanning, and compliance monitoring. MDR is a specific, deeper capability within the broader MSSP category.

Can MDR replace our internal security team?

MDR handles monitoring and detection, but your organization still needs someone to make risk decisions, manage security architecture, oversee compliance, and coordinate with the MDR provider. MDR replaces the SOC function, not the security leadership function.

How do we evaluate MDR response quality?

Ask for mean time to respond metrics, request sample incident reports, and ask about analyst-to-customer ratios. A provider with a 15-minute response SLA and 1:50 analyst-to-customer ratio delivers fundamentally different service than one with a 4-hour SLA and 1:200 ratio.

Fully Compliance provides educational content about IT compliance and cybersecurity. This article reflects current perspectives on managed detection and response services as of its publication date. MDR capabilities, pricing, and vendor offerings evolve continuously — consult qualified security professionals and current vendor documentation for evaluation guidance specific to your organization's requirements.