Who is the CISO of Quorum Cyber?

John Bruce is the current Chief Information Security Officer of Quorum Cyber on CISO Tribune's record, appointed in the week of November 24, 2025.

How many security-leadership moves has CISO Tribune tracked at Quorum Cyber?

CISO Tribune has tracked 1 move at Quorum Cyber since November 24, 2025.

When was John Bruce appointed at Quorum Cyber?

John Bruce's appointment as Chief Information Security Officer of Quorum Cyber was announced in the week of November 24, 2025, per Computer Weekly.

What does Quorum Cyber sell?

Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and Incident Response Services. Clarity Defend: Managed detection and response service providing 24/7 monitoring, detection and response to attacks. Clarity Extend: Enhanced security coverage extending monitoring to Microsoft Cloud and third-party technologies across an organization's IT ecosystem. Clarity Protect: Service that detects and stops threats, reduces cyber risk, and strengthens security across Microsoft and AI environments, including a CTEM offering. Clarity Data & AI: Service that helps organizations understand, protect and govern data, reducing exposure to insider threats and AI-related risks.

How does CISO Tribune file Quorum Cyber?

CISO Tribune files Quorum Cyber under MDR and managed SOC, with Incident response and forensics, Security consulting and advisory and OT and ICS security as secondary categories.

Where is Quorum Cyber headquartered?

Quorum Cyber is headquartered in Edinburgh, United Kingdom.

Company record · security vendor

Quorum Cyber CISO: John Bruce

CISO Tribune company record: Quorum Cyber, seat filled, since week of November 24, 2025

The current Chief Information Security Officer of Quorum Cyber, as tracked by CISO Tribune, is John Bruce, whose appointment was announced in the week of November 24, 2025 (Computer Weekly). Read the record. The record entered the Wire on September 30, 2026.

Career profile: John Bruce on CISO Spotlights ↗

Tracked by the Wire since November 24, 2025 · 1 recorded move · every claim links to a sourced record · Updated November 10, 2026

Where Quorum Cyber appears on the record (146)

Every page on CISO Tribune and its network that carries this company, 146 in all.

On the Wire: John Bruce named Chief Information Security Officer at Quorum Cyber · 2025-11-24
Career profile: John Bruce on CISO Spotlights ↗
Compared with (139): vs Accenture, vs AccessIT Group, vs Acronis, vs Agile Defense, vs Airbus, vs Alphabet, vs Arctic Wolf, vs Armis, vs Atos, vs BAE Systems, vs Barracuda Networks, vs Binary Defense, vs Bitdefender, vs BlackBerry, vs BlackCloak, vs Blackpoint Cyber, vs Blue Mantis, vs Booz Allen Hamilton, vs BreachRx, vs BSI, vs Capgemini, vs CGI, vs CISO Global, vs Claroty, vs Coalfire, vs CounterCraft, vs Critical Start, vs CyberProof, vs CyberTrust Consulting, vs Cybolt, vs Cyderes, vs Cynet, vs CYPFER, vs Cyrenity, vs D3 Security, vs Darktrace, vs Daylight, vs DeepSeas, vs Deepwatch, vs Defendify, vs DefenseStorm, vs Deutsche Telekom, vs Dispel, vs DXC Technology, vs Elbit Systems, vs eSentire, vs EverOak Solutions, vs Exaforce, vs Expel, vs Forescout, vs Forte Technologies, vs Fortified Health Security, vs FRSecure, vs Fujitsu, vs General Dynamics Information Technology, vs Grant Thornton, vs Guardz, vs GuidePoint Security, vs Helix, vs Hive Pro, vs Hold Security, LLC, vs Honeywell, vs Huntress, vs I-TRACING, vs IANS, vs ICF, vs IDEMIA, vs Indra Group, vs Indurex, vs Infosys, vs Integrity360, vs Intezer, vs Inversion6, vs iVerify, vs Judy Security, vs Keepnet Labs, vs KPMG, vs Kroll, vs Kudelski Security, vs Kyndryl, vs Leidos, vs Leonardo, vs Malwarebytes, vs Millennium Corporation, vs NCC Group, vs NCS, vs NEOX NETWORKS, vs Network Critical, vs NGC Risk, vs NINJIO, vs Northrop Grumman, vs Nozomi Networks, vs NTT DATA, vs Optiv, vs Orange Cyberdefense, vs Parsons, vs Pentio, vs Peraton, vs Phosphorus Cybersecurity, vs Proficio, vs Proximus NXT, vs PwC, vs Rackspace Technology, vs Rapid7, vs Red Canary, vs Reflex Security, vs Rockwell Automation, vs Saepio, vs SAIC, vs Secureworks, vs Semperis, vs SentinelOne, vs ServiceNow, vs Siemens, vs SonicWall, vs Sophos, vs Stellar Cyber, vs Surefire Cyber, vs Sygnia, vs Tata Consultancy Services, vs Tenable, vs Tenfold Security, vs Third Wave Innovations, vs Threat Intelligence, vs ThreatDefence, vs ThreatLocker, vs Trail of Bits, vs Trustwave, vs TXOne Networks, vs UltraViolet Cyber, vs UnderDefense, vs Unisys, vs UST, vs Veeam, vs Waterfall Security Solutions, vs White Hat IT Security, vs Wipro, vs WithSecure, vs Xage Security
In the vendor directory (5): MDR and managed SOC vendors · primary category
Incident response vendors: who they are and how CISOs compare them · category
Security consulting and advisory vendors · category
OT and ICS security vendors · category
SOC vendors: who they are and how CISOs compare them, from MDR to SIEM · vendor guide

About Quorum Cyber

CISO Tribune's Leadership Bench files Quorum Cyber under Cybersecurity Vendors and Europe. The Wire has one security-leadership move at Quorum Cyber on record, announced in the week of November 24, 2025.

Security leadership timeline

2025-11-24

John Bruce named Chief Information Security Officer at Quorum Cyber

Quorum Cyber, a Microsoft-focused cybersecurity firm, added John Bruce as Chief Information Security Officer among a group of senior executive hires.

What John Bruce has said in public

CISO Tribune's Voices section carries 1 public post or talk by John Bruce. The most recent are listed with their dates.

On the NCSC Annual Review, LinkedIn, November 3, 2026.

John Bruce's record

Security chiefs at other Cybersecurity Vendors organizations

Other organizations CISO Tribune files under Cybersecurity Vendors with a named security chief on record: those in Europe first, in alphabetical order from Quorum Cyber onward.

Filigran: Mathieu Rigotto, Chief Information Security Officer.
Keepit: Kim Larsen, group chief information security officer (CISO).
Outpost24: Olivia Brännlund, CISO.
RAD Security: Raj Umadas, Chief Information Security Officer (CISO).
RegScale: Dale Hoak, Chief Information Security Officer.
Rubrik: Michael Mestrovich, Chief Information Security Officer.
Sectigo: Jason Scott, Chief Information Security Officer.
Semperis: John Podboy, Chief Information Security Officer.

The full Cybersecurity Vendors bench

What the company sells

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.

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.

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.

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][8][9][10][11]}

Categories: MDR and managed SOC (primary category)
Incident response and forensics
Security consulting and advisory
OT and ICS security
Compare Quorum Cyber with companies in the same category
Headquarters: Edinburgh, United Kingdom^[1]
Founded: Not established from our sources
Ownership: Not established from our sources
CISO on record: John Bruce, Chief Information Security Officer (appointment announced in the week of November 24, 2025)
Website: quorumcyber.com

Products and services

Product names as the company writes them; what each does, in our words, from the company's own product pages. Never how well it does it.

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.

Competitors and alternatives

The other companies on our record filed under the same categories, category by category: first those that lead with that category and share more of Quorum Cyber's categories, then alphabetical. A list from the record, never a ranking.

On mdr and managed soc, Quorum Cyber competes with Inversion6, Kyndryl, Leonardo, White Hat IT Security, Arctic Wolf, Cyrenity, eSentire, Secureworks, Tenfold Security, Agile Defense and 54 more.
On incident response and forensics, Quorum Cyber competes with Sygnia, Kroll, BreachRx, CYPFER, Surefire Cyber, FRSecure, Inversion6, Kyndryl, Leonardo, White Hat IT Security and 27 more.
On security consulting and advisory, Quorum Cyber competes with Atos, FRSecure, Accenture, Booz Allen Hamilton, Coalfire, Cybolt, DXC Technology, I-TRACING, ICF, Infosys and 45 more.
On ot and ics security, Quorum Cyber competes with Honeywell, Claroty, Elbit Systems, Indurex, Northrop Grumman, Nozomi Networks, Rockwell Automation, Siemens, TXOne Networks, Xage Security and 19 more.

References

Every fact above cites one of these by number. Tier A is the company itself, a regulator or a filing; tier B is trade or business press.

[1]quorumcyber.comQuorum Cyber · quorumcyber.com · undated page, accessed October 7, 2026 · Tier A: the company, a regulator or a filing
[2]Difenda will rebrand as quorum cyberQuorum Cyber · quorumcyber.com · undated page, accessed October 7, 2026 · Tier A: the company, a regulator or a filing
[3]Microsoft Cyber Security Services Provider | Quorum CyberQuorum Cyber · undated page, accessed October 31, 2026 · Tier A: the company, a regulator or a filing
[4]About Quorum | Cyber Security CompanyQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[5]Why I’m Passionate about Protecting British Organisations from Cybercrime - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[6]Managed Security Services | Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[7]Cyber Resilience Assessment | Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[8]Quorum Cyber Managed XDR integrates with Microsoft Security Technology - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[9]Quorum Cyber is leveraging Copilot for Security at scale - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[10]Customers Informed of Microsoft Data Breach - Quorum CyberQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[11]Quorum Cyber appoints Chief Information Security OfficerQuorum Cyber · undated page, accessed November 10, 2026 · Tier A: the company, a regulator or a filing
[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: the company, a regulator or a filing

Last verified October 7, 2026. Our code found the quoted passage behind each fact on its source page when the fact was recorded, and re-checks every record against its sources each month.

Recorded October 7, 2026, expanded November 10, 2026 from the references above.

Work for Quorum Cyber? Suggest a correction to a fact on this page (with a source on your own domain), or claim this entry by publishing a small file on your domain.

Questions CISOs ask about Quorum Cyber

Who is the CISO of Quorum Cyber?: John Bruce is the current Chief Information Security Officer of Quorum Cyber on CISO Tribune's record, appointed in the week of November 24, 2025.
How many security-leadership moves has CISO Tribune tracked at Quorum Cyber?: CISO Tribune has tracked 1 move at Quorum Cyber since November 24, 2025.
When was John Bruce appointed at Quorum Cyber?: John Bruce's appointment as Chief Information Security Officer of Quorum Cyber was announced in the week of November 24, 2025, per Computer Weekly.
Who are the security chiefs at other Cybersecurity Vendors organizations?: On CISO Tribune's record they include Mathieu Rigotto at Filigran, Kim Larsen at Keepit, Olivia Brännlund at Outpost24 and Raj Umadas at RAD Security.
Has John Bruce spoken or written publicly?: CISO Tribune's Voices section carries 1 public post or talk by John Bruce, the most recent dated November 3, 2026.
What does Quorum Cyber sell?: Quorum Cyber sells Clarity Defend, Clarity Extend, Clarity Protect, Clarity Data & AI, Clarity OT and Incident Response Services. Clarity Defend: Managed detection and response service providing 24/7 monitoring, detection and response to attacks. Clarity Extend: Enhanced security coverage extending monitoring to Microsoft Cloud and third-party technologies across an organization's IT ecosystem. Clarity Protect: Service that detects and stops threats, reduces cyber risk, and strengthens security across Microsoft and AI environments, including a CTEM offering. Clarity Data & AI: Service that helps organizations understand, protect and govern data, reducing exposure to insider threats and AI-related risks.
How does CISO Tribune file Quorum Cyber?: CISO Tribune files Quorum Cyber under MDR and managed SOC, with Incident response and forensics, Security consulting and advisory and OT and ICS security as secondary categories.
Where is Quorum Cyber headquartered?: Quorum Cyber is headquartered in Edinburgh, United Kingdom.

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