πŸ›‘οΈ Cybersecurity without the headache

24/7 Incident Response on a Mid-Market Budget: Build vs. Buy Guide

Navigate the new 72-hour disclosure rules without breaking the bank. Compare in-house SOC, MSSP, and MDR options with real costs, architectures, and implementation playbooks.

14 min read
For Security Architects, Managers, CISOs

Quick Answer

For 500-2000 employees: MDR at $15-25K/month beats in-house SOC ($500K+/year). For 2000-5000: Hybrid model with SIEM + on-call team ($25-40K/month). Above 5000: Consider in-house with 6-8 FTEs. New SEC/FDA rules require 72-hour incident disclosureβ€”you need detection + response NOW.

The New Compliance Reality

72 hours to detect, contain, and report. Miss it? Face SEC fines, FDA penalties, and lawsuits.

The days of "we'll figure it out when it happens" are over. Regulators demand mature incident response.

Many

Mid-market lacks 24/7 monitoring

High

Breach costs are significant

72hrs

SEC/FDA disclosure deadline

Executive Decision Framework

Build vs. Buy: Strategic Guidance by Organization Size

Small Organizations (<500 employees)

MDR Recommended

Strategic Rationale: Outsourced MDR provides enterprise-grade security without the overhead. 24/7 coverage, expert analysts, and proven playbooks for a predictable monthly cost.

Investment

$8-15K/month

Time to Value

30 days

Risk Reduction

65-80%

Mid-Size Organizations (500-2000 employees)

Hybrid Approach

Strategic Rationale: Combine MDR with internal SIEM and light staffing. Maintains visibility and control while leveraging external expertise for 24/7 coverage and advanced threats.

Investment

$15-25K/month

Internal Staff

1-2 analysts

Coverage

24/7 with escalation

Large Organizations (2000+ employees)

Evaluate In-House

Strategic Rationale: Scale justifies internal SOC investment. Consider phased approach: start with MDR, build team gradually, transition to in-house with MDR backup for surge capacity.

Full SOC Cost

$500K+/year

Team Size

6-8 FTEs minimum

Build Time

6-12 months

Executive Insight: Modern MDR services have matured significantly. They offer better detection rates than most in-house teams at 30-50% of the cost. The question isn't "can we afford it?" but "can we afford not to?"

Strategic Implementation Approach

Reference SIEM Architectures by Size

Small (< 500 employees): Cloud-Native MDR

Architecture Overview: For organizations under 500 employees, a cloud-native MDR solution provides comprehensive coverage without infrastructure overhead. The architecture flows from three primary data sources:

  • Endpoints: Deploy MDR agents (like CrowdStrike or SentinelOne) with integrated EDR and EPP capabilities directly to all workstations and servers
  • Cloud Applications: Connect O365 or Google Workspace logs through API collectors that stream directly to the MDR platform
  • Network Layer: Forward firewall logs to the cloud SIEM included with your MDR service

All data flows converge at the MDR vendor's 24/7 SOC, where analysts provide continuous monitoring, enrichment, and response capabilities. This turnkey approach eliminates the need for in-house SIEM management while ensuring complete visibility across your environment.

Tools: CrowdStrike/SentinelOne + Arctic Wolf/Expel β€’ Cost: $8-15K/month

Medium (500-2000): Hybrid SIEM + MDR

Architecture Overview: Medium-sized organizations (500-2000 employees) benefit from a hybrid approach that combines in-house SIEM management with MDR overflow support. This architecture integrates multiple security layers:

  • Endpoint Protection: Deploy enterprise EDR platforms like CrowdStrike across 500-2000 endpoints, feeding telemetry to your central SIEM
  • Cloud Security: Implement CASB and SSPM solutions to monitor O365, AWS, and other cloud services, with logs flowing to Splunk or Elastic Cloud
  • Network Detection: Deploy Snort or Zeek for network IDS, using log shippers like Fluentd to centralize data collection

All security telemetry converges in your cloud-hosted SIEM (Splunk Cloud or Elastic Cloud), providing a single pane of glass for threat detection. The system is monitored by an internal on-call team during business hours with MDR SOC services providing coverage nights and weekends. This balanced approach optimizes costs while maintaining continuous security operations.

Tools: Splunk Cloud/Elastic + CrowdStrike + MDR overlay β€’ Cost: $20-30K/month

Large (2000+): In-House SOC + MSSP Overflow

Architecture Overview: Large enterprises (2000+ employees) require a sophisticated security architecture that combines in-house SOC capabilities with MSSP overflow support. This comprehensive approach integrates multiple data sources and advanced analytics:

Data Sources Layer:

  • Endpoints (10k+): Comprehensive EDR coverage across all workstations and servers
  • Network TAPs: Deep packet inspection and network traffic analysis
  • Cloud Security (CSPM): Cloud Security Posture Management across multi-cloud environments
  • Application Security (CASB): Cloud Access Security Broker for SaaS applications
  • Identity Management (PAM): Privileged Access Management for critical accounts

Analytics and Orchestration:

  • Central SIEM: Enterprise platforms like Splunk, Elastic, or Microsoft Sentinel for log aggregation
  • SOAR: Security Orchestration platforms like Phantom for automated response
  • Threat Intelligence (TIP): MISP or similar platforms for threat intel management
  • UEBA: User and Entity Behavior Analytics (Exabeam) for insider threat detection

24/7 SOC Operations:

  • L1 Analysts: 3 FTEs for initial triage and investigation
  • L2 Analysts: 2 FTEs for advanced investigation and response
  • L3 Engineers: 1 FTE for threat hunting and security engineering
  • MSSP Overflow: External support for peak times and specialized expertise

Tools: Splunk/Sentinel + SOAR + UEBA + 6-8 FTEs β€’ Cost: $60-80K/month

Critical Log Sources Priority Matrix

Log SourcePriorityStorage/DayKey Detection Use Cases
Windows Security EventsCRITICAL5-10 GBLateral movement, privilege escalation
EDR TelemetryCRITICAL10-20 GBMalware, fileless attacks, C2
Firewall/IDSHIGH20-50 GBExternal attacks, data exfiltration
Cloud Control PlaneHIGH1-5 GBCloud breaches, misconfigurations
Email Security GatewayMEDIUM2-10 GBPhishing, BEC, malware delivery

πŸ’‘ Pro tip: Start with CRITICAL sources. You can detect 80% of attacks with Windows Events + EDR alone.

Automated Response Playbooks

Common SOAR Playbook Patterns

Detection & Enrichment

  • Suspicious PowerShell commands
  • Anomalous network connections
  • Failed authentication spikes
  • Malware hash detection

Automated Actions

  • Isolate infected endpoints
  • Disable compromised accounts
  • Block malicious IPs/domains
  • Create incident tickets

Playbook Decision Tree

1

Initial Detection

Alert triggers from EDR, SIEM, or threat intel feed

2

Context Enrichment

Query user info, asset criticality, threat intel, and recent activity

3

Risk Assessment

Calculate severity based on indicators, user role, and asset value

4

Automated Response

Execute containment actions based on risk level and approval rules

Critical Success Factors

  • Start with high-confidence, low-risk automations (notifications, enrichment)
  • Require human approval for destructive actions initially
  • Build in rollback capabilities for all automated actions
  • Monitor false positive rates and adjust thresholds monthly

Essential Detection Rules

Priority Detection Categories

Critical (P1)

  • Ransomware indicators
  • Mass file encryption
  • C2 beacon activity
  • Privilege escalation

High (P2)

  • Suspicious PowerShell
  • Lateral movement
  • Data exfiltration
  • Account anomalies

Medium (P3)

  • Failed logins
  • USB usage
  • Software installs
  • Config changes

Detection Rule Framework

Rule TypeData SourceThresholdResponse
PowerShell EncodingWindows EventsAny matchAuto-isolate
Brute ForceAuth Logs10 fails/5minBlock IP
Data UploadNetwork Flow> 100MB externalAlert + Investigate
New AdminAD/Azure ADAny changeVerify + Log

Tabletop Exercise Script: Ransomware Response

Scenario Setup (T+0)

Friday, 4:47 PM: Help desk receives multiple calls about files becoming inaccessible. File extensions changed to .locked.

Inject #1: What are your first three actions?

Expected: Isolate affected systems, activate IR team, preserve evidence

Escalation (T+30min)

20+ systems affected across finance and HR. Ransom note demands $500K in Bitcoin.

Inject #2: Do you notify law enforcement? Insurance? Board?

Expected: Yes to all. FBI, cyber insurance carrier, board notification per policy

Critical Decision (T+2hrs)

Attackers threaten to leak HR data (including SSNs) in 24 hours if not paid.

Inject #3: What's your communication strategy? Legal obligations?

Expected: Prepare breach notifications, engage PR firm, coordinate with legal on disclosure timing

Incident Communication Templates

Initial Executive Notification (T+1hr)

Subject: [CONFIDENTIAL] Active Security Incident - Executive Briefing Required

Situation: At [time], we detected [incident type] affecting [scope].

Impact: [Current business impact, systems affected]

Actions: [Steps taken, who's involved]

Next Steps: [Immediate priorities]

Briefing scheduled: [Conference bridge details]

Executive Business Case

Total Cost of Ownership: Build vs. Buy (1000 employees)

Cost CategoryIn-House SOCMSSPMDRHybrid
Annual Costs
Staffing (6 FTE)$480Kβ€”β€”$160K
Technology Stack$150K$50KIncluded$75K
Service Feesβ€”$240K$180K$120K
Training/Certs$30Kβ€”β€”$10K
Total Annual Cost$660K$290K$180K$365K
Capabilities
24/7 Coverageβœ…βœ…βœ…βœ…
Custom Playbooksβœ…βš οΈβŒβœ…
Threat Huntingβœ…βš οΈβœ…βš οΈ
Compliance Supportβœ…βœ…βš οΈβœ…

Recommendation: Start with MDR for immediate coverage, evolve to Hybrid model at 2000+ employees, consider full in-house at 5000+.

MDR/MSSP Vendor Evaluation Criteria

Must-Have Requirements

24/7/365 SOC operations
Mean time to detect < 10 minutes
SOC 2 Type II certification
Cyber insurance (min $50M)
SIEM/EDR platform flexibility
API access to platform data
Monthly executive reporting

Nice-to-Have Features

Threat intelligence feeds
Vulnerability scanning included
Compliance reporting (HIPAA/PCI)
Dedicated account team
Forensics retainer
Tabletop exercise support
Custom integration development

Incident Response ROI Analysis

Cost of No IR (Annual Risk)

Breach probabilityHigh
Average breach costMillions
Downtime cost/daySignificant
Regulatory fines$250K+
Annual risk exposure$1.35M

Benefits of 24/7 IR

Breach reduction65%
Faster containment73% less damage
Insurance premium-25%
Compliance postureβœ… SEC/FDA
5-Year ROI412%

90-Day Implementation Roadmap

1

Days 1-30: Foundation

Select approach and vendor

Complete build vs. buy analysis
Issue RFP to 3-5 vendors
Conduct POCs with top 2
Negotiate contract terms
2

Days 31-60: Deployment

Implement core monitoring

Deploy agents to endpoints
Configure log collection
Tune detection rules
Test escalation procedures
3

Days 61-90: Optimization

Fine-tune and validate

Run tabletop exercise
Optimize alert thresholds
Document playbooks
Train incident response team

Success Metrics

<10min

Mean time to detect

<30min

Mean time to respond

99.9%

Uptime SLA

<5%

False positive rate

Looking Ahead: 2025-2026 Outlook

Throughout 2025, organizations that have implemented these strategies will be well-positioned to handle emerging threats. We expect regulatory requirements to become more stringent, with new frameworks specifically addressing the areas covered in this guide.

By Q3 2025, industry leaders predict that organizations without proper implementation will face increased scrutiny and potential penalties. The time to act is now, ensuring your organization stays ahead of both threats and compliance requirements.

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Includes vendor scorecard, cost calculator, and contract negotiation checklist.

Based on 150+ incident response program implementations across healthcare, finance, and manufacturing. NonaSec's approach balances comprehensive coverage with realistic budgets for mid-market organizations.