CISO Tribune

Vendor comparison · 2 companies

Critical Start vs Quorum Cyber

Critical Start sells managed detection and response (MDR) that combines AI-powered triage with human-led investigation. Quorum Cyber delivers Microsoft-first, threat-led cyber security services. CISO Tribune files both under MDR and managed SOC. This page sets the two records side by side: what each sells, where it is based, who owns and funds it, the customers it names and its recent news, each fact numbered to its source.

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  • Critical Start
  • Quorum Cyber
Critical Start vs Quorum Cyber: Products, Customers and Funding Compared
Critical StartCritical Start sells managed detection and response (MDR) that combines AI-powered triage with human-led investigation.criticalstart.comQuorum CyberQuorum Cyber delivers Microsoft-first, threat-led cyber security services.quorumcyber.com
What it sells
  • CORR Platform[4]The MDR platform that gives a security operations team visibility into every alert, investigation and response action.
  • Managed Detection and Response[3][10][11]MDR that combines AI-powered triage with human-led investigation.
  • Service Credits[7]A prepaid, flexible currency included in every managed service contract.
  • Vulnerability Management Services[3]Vulnerability management delivered under the same tier structure as MDR.
  • MobileSOC[12]A native iOS and Android application for real-time security operations management.
  • Clarity Defend[1][3][6]Managed detection and response service providing 24/7 monitoring, detection and response to attacks.
  • Clarity Extend[1][3]Enhanced security coverage extending monitoring to Microsoft Cloud and third-party technologies across an organization's IT ecosystem.
  • Clarity Protect[1][3]Service that detects and stops threats, reduces cyber risk, and strengthens security across Microsoft and AI environments, including a CTEM offering.
  • Clarity Data & AI[1][3]Service that helps organizations understand, protect and govern data, reducing exposure to insider threats and AI-related risks.
  • Clarity OT[3]Managed detection and response service for operational technology environments.
  • Incident Response Services[3]Services including incident response preparedness, retainer agreements, and emergency MDR for breach investigation and containment.
Categories
Headquarters
Not stated on its pagesEdinburgh, United Kingdom[1]
Founded
Not stated on its pagesNot stated on its pages
Ownership and funding
Not stated on its pagesNot stated on its pages
Named customers
Not stated on its pagesNot stated on its pages
Recent news
  • July 22, 2026Critical Start announced the appointment of Francine Geist as Chief Executive Officer, effective immediately.[9]
  • June 3, 2026Critical Start released SOC AI, a multi-agent framework that powers its AI-led managed detection and response service.[11]
  • June 2, 2026Critical Start released SOC AI, a multi-agent framework that powers its AI-led managed detection and response service.[10]
  • September 16, 2026Quorum Cyber announced that it has signed a definitive agreement to acquire Ontinue, a managed extended detection and response provider.[12]
G2 and Gartner Peer Insights
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
Who it fits
From its own pages, Critical Start sells mainly to organizations that need accountability from a managed security provider, with contractual SLA commitments as the central offer. The company says it protects financial services firms, healthcare systems, manufacturers and utilities. For financial institutions, it describes ransomware, wire fraud and insider threats as the threats its MDR addresses. Its compliance reporting covers frameworks such as PCI DSS, HIPAA and NERC CIP, which points to regulated buyers. Critical Start MDR works with the customer's existing tools, so it suits teams that want to keep the security products they already run.Not written yet
Last verified
September 27, 2026October 7, 2026

Where they overlap

  • MDR and managed SOC is the primary category of both Critical Start and Quorum Cyber.

Where they differ, field by field

  • Quorum Cyber is also filed under Incident response and forensics, Security consulting and advisory and OT and ICS security.
  • Critical Start lists CORR Platform, Managed Detection and Response, Service Credits, Vulnerability Management Services and MobileSOC. Quorum Cyber lists Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more.
  • Quorum Cyber is headquartered in Edinburgh, United Kingdom.

How they differ

CISO Tribune files both Critical Start and Quorum Cyber under MDR and managed SOC as their primary category. Critical Start sells Managed Detection and Response that combines AI-powered triage with human-led investigation, along with the CORR Platform, MobileSOC and Vulnerability Management Services. Its CORR platform connects to a security stack through native APIs, with no proprietary agents. Quorum Cyber is also filed under incident response and forensics, security consulting and advisory, and OT and ICS security. Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI and Clarity OT, plus Incident Response Services.

Quorum Cyber is headquartered in Edinburgh, United Kingdom, and describes its services as Microsoft-first. It is a Microsoft Solutions Partner for Security and works with Microsoft 365 Defender and Microsoft Sentinel. Critical Start says its MDR works with the customer's existing tools, and its analysts contain threats directly in those tools through 30+ advanced integrations. Critical Start backs every response time with a contractual SLA.

Critical Start says it protects financial services firms, healthcare systems, manufacturers and utilities across 7 continents. Quorum Cyber states that it protects 400+ organisations across four continents. On July 22, 2026, Critical Start announced the appointment of a new Chief Executive Officer, effective immediately. On June 3, 2026, Critical Start released SOC AI, a multi-agent framework that powers its AI-led managed detection and response service. On September 16, 2026, Quorum Cyber announced a definitive agreement to acquire Ontinue, a managed extended detection and response provider.

What it sells: Critical Start

What CORR Platform does[4]
CORR connects to a security stack through native APIs, with no proprietary agents and no forced replacements. It works through API-based integrations, with no agents to deploy and no additional infrastructure to manage.
What Managed Detection and Response does[3][10][11]
Critical Start MDR combines AI-powered triage with human-led investigation and backs every response time with a contractual SLA. Analysts contain threats directly in the customer's tools through 30+ advanced integrations.
What Service Credits does[7]
Every managed service contract includes service credits that can be spent across 30+ services. MDR for Endpoint, MDR for SIEM and VMS each include credits. Credits stack into a single bank when a customer has more than one.

Questions about Critical Start and Quorum Cyber

What do Critical Start and Quorum Cyber sell?
Critical Start sells CORR Platform, Managed Detection and Response, Service Credits, Vulnerability Management Services and MobileSOC. Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more.
Are Critical Start and Quorum Cyber in the same category?
Yes. MDR and managed SOC is the primary category of both on CISO Tribune.
Where are Critical Start and Quorum Cyber headquartered?
Quorum Cyber is headquartered in Edinburgh, United Kingdom.
Who are Critical Start and Quorum Cyber sold to?
From its own pages, Critical Start sells mainly to organizations that need accountability from a managed security provider, with contractual SLA commitments as the central offer.
What have Critical Start and Quorum Cyber announced recently?
July 22, 2026: Critical Start announced the appointment of Francine Geist as Chief Executive Officer, effective immediately. September 16, 2026: Quorum Cyber announced that it has signed a definitive agreement to acquire Ontinue, a managed extended detection and response provider.

About Critical Start

Critical Start sells managed detection and response (MDR) that combines AI-powered triage with human-led investigation. The company says tools produce thousands of alerts every day, and that Critical Start MDR works to resolve every one and backs every response time with a contractual SLA.[2][6]

CORR is the MDR platform that Critical Start uses to give a security operations team visibility into every alert, every investigation and every response action. CORR connects to a security stack through native APIs, with no proprietary agents and no forced replacements. Critical Start says CORR connects to an existing stack through API-based integrations, with no agents to deploy, no network architecture changes and no additional infrastructure to manage.[1][4][5]

More than 30 of these are advanced integrations where Critical Start analysts contain threats directly in the customer's tools. Inside the platform, AI agents analyze enriched case data, including URL analysis, suggested verdicts and investigation summaries. A certified SOC analyst validates every finding, with two-person verification on critical alerts. The Trusted Behavior Registry uses deterministic behavioral validation to auto-resolve 99.83% of known-good behaviors before a human analyst sees them.[5]

Critical Start also offers MobileSOC, a native iOS and Android application for real-time security operations management. CORR supports compliance reporting for SOC 2, ISO 27001, PCI DSS, HIPAA, GLBA, CMMC and NERC CIP.

Every managed service follows an Essentials, Enterprise and Signature packaging model. That tier structure applies across MDR for Endpoint, MDR for SIEM and Vulnerability Management Services (VMS).

Every Critical Start managed service contract includes service credits, a prepaid, flexible currency that can be spent across 30+ services. Essentials includes 5 credits, Enterprise includes 10 credits and Signature includes 20 credits per subscription. MDR for Endpoint, MDR for SIEM and VMS each include credits, and credits stack into a single bank when a customer holds more than one.[7]

Critical Start says that in 2012 three security experts who had led incident response and threat hunting at Fortune 500 companies recognized a gap in the market. The company says it protects financial services firms, healthcare systems, manufacturers and utilities across 7 continents. For financial institutions, Critical Start delivers MDR with contractual SLAs and audit-grade investigation documentation.[4][5][6][8]

Critical Start on the record

Sources

Critical Start full record

  1. [1]PlatformCritical Start · criticalstart.com · undated page, accessed September 27, 2026 · Tier A
  2. [2]Critical Start | Managed Detection and Response (MDR)Critical Start · undated page, accessed October 24, 2026 · Tier A
  3. [3]Managed Security Services | Critical StartCritical Start · undated page, accessed October 24, 2026 · Tier A
  4. [4]Security Integrations | Critical StartCritical Start · undated page, accessed October 24, 2026 · Tier A
  5. [5]Security Solutions by Environment | Critical StartCritical Start · undated page, accessed October 24, 2026 · Tier A
  6. [6]About Critical Start | Cybersecurity CompanyCritical Start · undated page, accessed October 24, 2026 · Tier A
  7. [7]Service Credits: Flexible Security Currency | Critical StartCritical Start · undated page, accessed October 24, 2026 · Tier A
  8. [8]MDR for Finance: PCI, SOX, SOC 2 | Critical StartCritical Start · undated page, accessed October 24, 2026 · Tier A
  9. [9]Critical Start Appoints Francine Geist as Chief Executive OfficerCritical Start · published July 22, 2026 · Tier A
  10. [10]Critical Start Delivers SOC AI: A Production-Proven Agentic Architecture Built for Auditable, Human-Validated MDRBusiness Wire · published June 2, 2026 · Tier A
  11. [11]Critical Start expands MDR capabilities with multi-agent AI systemHelp Net Security · published June 3, 2026 · Tier B
  12. [12]CORR Platform: See Everything. Question Nothing. | Critical StartCritical Start · undated page, accessed November 5, 2026 · Tier A

Quorum Cyber full record

  1. [1]quorumcyber.comQuorum Cyber · quorumcyber.com · undated page, accessed October 7, 2026 · Tier A
  2. [2]Difenda will rebrand as quorum cyberQuorum Cyber · quorumcyber.com · undated page, accessed October 7, 2026 · Tier A
  3. [3]Microsoft Cyber Security Services Provider | Quorum CyberQuorum Cyber · undated page, accessed October 31, 2026 · Tier A
  4. [4]About Quorum | Cyber Security CompanyQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  5. [5]Why I’m Passionate about Protecting British Organisations from Cybercrime - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  6. [6]Managed Security Services | Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  7. [7]Cyber Resilience Assessment | Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  8. [8]Quorum Cyber Managed XDR integrates with Microsoft Security Technology - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  9. [9]Quorum Cyber is leveraging Copilot for Security at scale - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  10. [10]Customers Informed of Microsoft Data Breach - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  11. [11]Quorum Cyber appoints Chief Information Security OfficerQuorum Cyber · undated page, accessed November 10, 2026 · Tier A
  12. [12]Quorum Cyber Announces Intent to Acquire Ontinue, Building an Unrivaled Microsoft-First Agentic SOC for the Autonomous Threat EraPRNewswire · published September 16, 2026 · Tier A

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