CISO Tribune

Vendor comparison · 2 companies

Quorum Cyber vs UnderDefense

Quorum Cyber delivers Microsoft-first, threat-led cyber security services. UnderDefense sells UnderDefense MAXI, a security and compliance automation platform, and an MDR service in which security experts monitor, detect and respond to incidents. 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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Up to four companies side by side.

  • Quorum Cyber
  • UnderDefense
Quorum Cyber vs UnderDefense: Products, Customers and Funding Compared
Quorum CyberQuorum Cyber delivers Microsoft-first, threat-led cyber security services.quorumcyber.comUnderDefenseUnderDefense sells UnderDefense MAXI, a security and compliance automation platform, and an MDR service in which security experts monitor, detect and respond to incidents.underdefense.com
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.
  • UnderDefense MAXI[1][2][3][5][6]A security and compliance automation platform. UnderDefense MAXI integrates with SIEMs, firewalls and endpoint protection solutions.
  • UnderDefense Agentic AI SOC[4]AI agents investigate each alert. Analysts on shift 24/7 decide what happens next.
  • MDR[1][2][6]Security experts monitor, detect and respond to incidents.
  • Cloud-based SIEM[2]A cloud-based SIEM that collects, analyzes and responds to security events.
  • CIS AWS Benchmark assessment[8]A self-service assessment of AWS security.
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 pagesNot stated on its pages
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]
Not stated on its pages
G2 and Gartner Peer Insights
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
  • G2: listed, seen November 10, 2026[10]
  • Gartner Peer Insights: Not stated on its pages
Who it fits
Not written yetUnderDefense MAXI integrates with a customer's security infrastructure, including SIEMs, firewalls and endpoint protection solutions. UnderDefense offers compliance templates to organizations working toward standards such as SOC2 and ISO 27001. UnderDefense MAXI provides executive-level reports for C-level readers.
Last verified
October 7, 2026October 26, 2026

Where they overlap

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

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. UnderDefense is also filed under Penetration testing and red team services, Compliance automation and SOAR and security automation.
  • Quorum Cyber lists Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more. UnderDefense lists UnderDefense MAXI, UnderDefense Agentic AI SOC, MDR, Cloud-based SIEM and CIS AWS Benchmark assessment.
  • Quorum Cyber is headquartered in Edinburgh, United Kingdom.

How they differ

CISO Tribune files both Quorum Cyber and UnderDefense under MDR and managed SOC as their primary category, but their other filings differ. Quorum Cyber is also filed under incident response and forensics, security consulting and advisory, and OT and ICS security. UnderDefense is also filed under penetration testing and red team services, compliance automation, and SOAR and security automation.

Quorum Cyber is headquartered in Edinburgh, United Kingdom, and describes its services as Microsoft-first. It sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI and Clarity OT, which is a managed detection and response service for operational technology environments. Quorum Cyber is a Microsoft Solutions Partner for Security and works with Microsoft 365 Defender and Microsoft Sentinel. It also sells Incident Response Services that include retainer agreements. Quorum Cyber states that it protects 400+ organisations across four continents. On September 16, 2026, Quorum Cyber announced a definitive agreement to acquire Ontinue, a managed extended detection and response provider.

UnderDefense sells UnderDefense MAXI, a security and compliance automation platform that integrates with SIEMs, firewalls and endpoint protection solutions. UnderDefense MAXI provides pre-built compliance templates for standards such as SOC2 and ISO 27001. UnderDefense also sells an MDR service, an Agentic AI SOC in which AI agents investigate each alert while analysts on shift 24/7 decide what happens next, and a cloud-based SIEM. It offers a self-service CIS AWS Benchmark assessment of AWS security as well. UnderDefense serves organizations across five continents that represent multiple industries. It took part, in cooperation with the Computer Emergency Response Team of Ukraine (CERT-UA), in a series of Incident Response cases.

What it sells: UnderDefense

What UnderDefense MAXI does[1][2][3][5][6]
UnderDefense MAXI natively monitors endpoints, networks, users and decoy beacons. UnderDefense MAXI provides ready-to-use playbooks, AI-powered alert enrichment and notifications through Slack, Jira or a preferred tool. UnderDefense MAXI provides pre-built compliance templates for standards such as SOC2 and ISO 27001.
What UnderDefense Agentic AI SOC does[4]
UnderDefense Agentic AI SOC uses AI agents that investigate each alert. Analysts on shift 24/7 decide what happens next.
What CIS AWS Benchmark assessment does[8]
UnderDefense offers a self-service CIS AWS Benchmark assessment. The assessment covers evaluating the maturity of cloud security controls, identifying misconfigurations, providing detailed mitigation instructions and giving a summary table with a final CVSS v3.0 score.

Questions about Quorum Cyber and UnderDefense

What do Quorum Cyber and UnderDefense sell?
Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and 1 more. UnderDefense sells UnderDefense MAXI, UnderDefense Agentic AI SOC, MDR, Cloud-based SIEM and CIS AWS Benchmark assessment.
Are Quorum Cyber and UnderDefense in the same category?
Yes. MDR and managed SOC is the primary category of both on CISO Tribune.
Where are Quorum Cyber and UnderDefense headquartered?
Quorum Cyber is headquartered in Edinburgh, United Kingdom.
Who are Quorum Cyber and UnderDefense sold to?
UnderDefense MAXI integrates with a customer's security infrastructure, including SIEMs, firewalls and endpoint protection solutions.
What have Quorum Cyber and UnderDefense 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.

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

UnderDefense full record

  1. [1]underdefense.comUnderDefense · underdefense.com · undated page, accessed October 26, 2026 · Tier A
  2. [2]Compliance PricingUnderDefense · undated page, accessed November 10, 2026 · Tier A
  3. [3]Agentic AI SOC & Compliance Automation Platform | UnderDefenseUnderDefense · undated page, accessed November 10, 2026 · Tier A
  4. [4]Elastic Cloud Pricing 2026: Serverless, Hosted, and SIEMUnderDefense · undated page, accessed November 10, 2026 · Tier A
  5. [5]Cloudflare Pricing 2026: WAF, Zero Trust, and EnterpriseUnderDefense · undated page, accessed November 10, 2026 · Tier A
  6. [6]Palo Alto Networks Pricing 2026: Firewalls, SASE, and XDRUnderDefense · undated page, accessed November 10, 2026 · Tier A
  7. [7]2025 MXDR Pricing Guide: Choosing the Right MXDR providerUnderDefense · undated page, accessed November 10, 2026 · Tier A
  8. [8]Episode 4: Cyber Resilience 201 — AWS Cloud Security - UnderDefenseUnderDefense · undated page, accessed November 10, 2026 · Tier A
  9. [9]E-Mail Under Attack - UnderDefenseUnderDefense · undated page, accessed November 10, 2026 · Tier A
  10. [10]UnderDefense MAXI Reviews & Product DetailsG2 · undated page, accessed November 10, 2026 · Tier C

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