CISO Tribune

Vendor comparison · 2 companies

Quorum Cyber vs Stellar Cyber

Quorum Cyber delivers Microsoft-first, threat-led cyber security services. Stellar Cyber sells a SecOps platform that uses AI for threat detection and response through unified NG-SIEM, NDR, and Open XDR capabilities. 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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  • Quorum Cyber
  • Stellar Cyber
Quorum Cyber vs Stellar Cyber: Products, Customers and Funding Compared
Quorum CyberQuorum Cyber delivers Microsoft-first, threat-led cyber security services.quorumcyber.comStellar CyberStellar Cyber sells a SecOps platform that uses AI for threat detection and response through unified NG-SIEM, NDR, and Open XDR capabilities.stellarcyber.ai
What it sells
  • 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.
  • Stellar Cyber Open XDR PlatformA SecOps platform that unifies SIEM, network detection and response, identity threat detection and response, and behavior analytics with AI-driven detection, investigation and response.
Categories
Headquarters
Edinburgh, United Kingdom[1]Not stated on its pages
Founded
Not stated on its pagesNot stated on its pages
Ownership and funding
Not stated on its pagesPrivately held[3][4]
Named customers
Not stated on its pagesNot stated on its pages
Recent news
  • September 16, 2026Quorum Cyber announced that it has signed a definitive agreement to acquire Ontinue, a managed extended detection and response provider.[12]
  • October 5, 2026Stellar Cyber announced version 7.0 of its security operations platform, adding AI case triage, case metrics and expanded automated response.[16]
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
Not written yetStellar Cyber describes its open SecOps platform as built for lean security teams and MSSPs. Stellar Cyber designs its enterprise platform for security teams of any size or skill level. Stellar Cyber Open XDR can be deployed on-premises, from the cloud, or co-managed by an MSSP.
Last verified
October 7, 2026November 9, 2026

Where they overlap

  • Quorum Cyber and Stellar Cyber are both filed under MDR and managed SOC.

Where they differ, field by field

  • Quorum Cyber's primary category is MDR and managed SOC; Stellar Cyber's is SIEM.
  • Quorum Cyber is also filed under Incident response and forensics, Security consulting and advisory and OT and ICS security. Stellar Cyber is also filed under AI SOC analysts.
  • Quorum Cyber lists Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more. Stellar Cyber lists Stellar Cyber Open XDR Platform.
  • Quorum Cyber is headquartered in Edinburgh, United Kingdom.
  • Stellar Cyber is privately held.

Questions about Quorum Cyber and Stellar Cyber

What do Quorum Cyber and Stellar Cyber sell?
Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more. Stellar Cyber sells Stellar Cyber Open XDR Platform.
Are Quorum Cyber and Stellar Cyber in the same category?
They share MDR and managed SOC. Quorum Cyber's primary category is MDR and managed SOC and Stellar Cyber's is SIEM.
Where are Quorum Cyber and Stellar Cyber headquartered?
Quorum Cyber is headquartered in Edinburgh, United Kingdom.
Who owns Quorum Cyber and Stellar Cyber?
Stellar Cyber is privately held.
Who are Quorum Cyber and Stellar Cyber sold to?
Stellar Cyber describes its open SecOps platform as built for lean security teams and MSSPs.
What have Quorum Cyber and Stellar Cyber announced recently?
September 16, 2026: Quorum Cyber announced that it has signed a definitive agreement to acquire Ontinue, a managed extended detection and response provider. October 5, 2026: Stellar Cyber announced version 7.0 of its security operations platform, adding AI case triage, case metrics and expanded automated response.

About Quorum Cyber

Quorum Cyber delivers Microsoft-first, threat-led cyber security services. Quorum Cyber was founded in Edinburgh in 2016. Federico Charosky founded Quorum Cyber. Quorum Cyber is a Microsoft Solutions Partner for Security and works with the Microsoft Security stack, including Microsoft 365 Defender and Microsoft Sentinel.

Quorum Cyber says AI changes how organisations work and how attackers operate. Quorum Cyber helps security teams protect data, manage emerging risks and enable secure adoption.

Clarity is more than the name of Quorum Cyber's customer platform and managed security services. Quorum Cyber unifies Microsoft 365 Defender and Microsoft Sentinel in Clarity, turning raw signals into prioritised incidents. Quorum Cyber offers three managed detection and response services, plus a dedicated data security service.[6]

Quorum Cyber's Cyber Resilience Assessment evaluates how well an organisation can manage cyber disruption. Quorum Cyber's Security Maturity Assessment looks at the effectiveness of a wider security programme, including governance, controls and risk management.[7]

Quorum Cyber has an Incident Response team that helps organisations investigate and manage cyber incidents. Quorum Cyber's Security Operations Centre works to detect and respond to customer threats. Quorum Cyber offers an incident response retainer that customers can initiate. Quorum Cyber offers Managed XDR, which integrates with Microsoft Security Technology. Quorum Cyber works with the generative AI capabilities of Copilot for Security to help defend customers against cyber threats. Quorum Cyber has a Threat Intelligence team. Following two acquisitions in 2024, Quorum Cyber's services range from phishing simulation and managed services to incident response and ransom negotiation.[7][8][9][10]

Quorum Cyber states that it protects 400+ organisations across four continents. Quorum Cyber has over 350 employees across the UK, US, Canada and UAE. Quorum Cyber is also a member of the Microsoft Intelligent Security Association and a Microsoft Security Copilot Partner.[6][7][11]

Quorum Cyber on the record

Sources

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

Stellar Cyber full record

  1. [1]ProductStellar Cyber · stellarcyber.ai · published February 25, 2026 · Tier A
  2. [2]Stellar cyber announces agentic ai autonomous soc in 6 4 0 releaseStellar Cyber · stellarcyber.ai · published March 16, 2026 · Tier A
  3. [3]Stellar cyber named one of americas best startup employersStellar Cyber · stellarcyber.ai · published November 21, 2024 · Tier A
  4. [4]ISOC Platform with AI SIEM, NDR, Open XDR & Multi-Layer AIStellar Cyber · undated page, accessed October 29, 2026 · Tier A
  5. [5]Stellar Cyber Automation-driven SecOps PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  6. [6]Stellar Cyber vs Sumo Logic: Expert SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  7. [7]Stellar Cyber vs Splunk: In-Depth SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  8. [8]Integrated Security Operations Center (ISOC) PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  9. [9]SC vs Microsoft Sentinel: Comprehensive SIEM SolutionStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  10. [10]SC vs. CrowdStrike | Compare Leading Cybersecurity PlatformsStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  11. [11]EDR Software, Endpoint Detection & ResponseStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  12. [12]Stellar Cyber Autonomous SOC PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  13. [13]Stellar Cyber Multi-Layer AI™ | Advanced AI Platform for SecOpsStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  14. [14]Stellar Cyber AI SIEM | AI-Driven SIEM PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  15. [15]Stellar Cyber vs AlienVault: In-Depth SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  16. [16]Stellar Cyber 7.0 Makes the Agentic SOC Measurable, Actionable and Operational at ScaleStellar Cyber · published October 5, 2026 · Tier A

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