GreyCastle Security
GreyCastle Security is a private US cybersecurity services firm founded in 2011 and headquartered in Troy, dedicated exclusively to cybersecurity and the practical management of cybersecurity risks for its clients.
- Company typePrivate
- Founded2011
- HeadquartersTroy, United States
- Headcount11–50
- GTM typeB2B
- OfferingServices
What GreyCastle Security does
GreyCastle Security is a private, for-profit cybersecurity services provider founded in 2011 and headquartered in Troy, United States, operating with a headcount band of 11–50 employees. Per its firmographic description, the company is dedicated exclusively to cybersecurity and the practical management of cybersecurity risks, implying a specialized, services-oriented model rather than a product-licensing business. No product portfolio, pricing structure, or revenue streams are disclosed for GreyCastle in the input; the firm does not appear to be a platform vendor based on its stated positioning.
In terms of strategic activity, GreyCastle Security acquired Orange Parachute on 2017-11-16 for an undisclosed amount, representing a single inorganic capability expansion in the observable record. The leadership team consists of Reg Harnish (founder), Michael Stamas (co-founder and VP), Dan Kalil (Board Chairman and CEO), Dan Maynard (COO), Ho Chin (CFO), David Ross (Chief Privacy Officer), Dan Didier (VP of Solutions and Product Management), and Keith Robertson (Chief Security Architect), indicating a leadership structure that spans executive, financial, privacy, and technical-architecture functions within a small specialist practice.
The evidence base for GreyCastle Security specifically is narrow: most of the provided source material pertains to a distinct entity (DeepSeas) and is explicitly flagged in the source notes as not relating to GreyCastle Security. Consequently, customer logos, revenue figures, AI/ML capabilities, certifications, partnerships, and product descriptions in the input cannot be attributed to GreyCastle and are excluded from this analysis.
GreyCastle Security firmographics
Firmographics- Name
- GreyCastle Security
- Legal name
- Not available - source data pertains to DeepSeas, not GreyCastle Security
- Website
- https://greycastlesecurity.com
- Company type
- Private
- Founded year
- 2011
- Headcount range
- 11–50 employees
- Short description
- GreyCastle Security is a private US cybersecurity services firm founded in 2011 and headquartered in Troy, dedicated exclusively to cybersecurity and the practical management of cybersecurity risks for its clients.
- Ownership category
- akta.pro rank
GreyCastle Security industry classification
Industry- Product category
- Cybersecurity Services
- NAICS
- Investigation and Security Services (5616), Security Systems Services (56162)
- SIC
- Services-Engineering, Accounting, Research, Management (8700)
- akta.pro primary industry
- Network Security Managed Services (Firewall/IDS/IPS/SASE) (BPAEADAG)
- akta.pro secondary industry
- OT/ICS & Critical Infrastructure Cybersecurity Services (BPAKAHAN)
Keywords
Where GreyCastle Security is headquartered
LocationHeadquarters
- HQ city
- Troy
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
GreyCastle Security business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Technology or R&D, Operations, Marketing or Sales
Revenue model
- Managed Security Services: Recurring subscription-based managed detection and response services providing continuous 24/7 monitoring, detection, and response capabilities for client environments.
- Professional Security Services: One-time and project-based offensive security assessments, penetration testing, strategic security advisory, and compliance consulting services.
Distribution channels1 record
Marketing channels4 records
GreyCastle Security product offering
Product offeringCore offering
GreyCastle Security is a service provider dedicated exclusively to cybersecurity and the practical management of cybersecurity risks. The firm delivers managed detection and response, offensive security testing, threat intelligence, governance risk and compliance, a dedicated CyberFusion SOC, and strategic C-suite security advisory under unified programs. Customers can purchase individual services or a bundled full-coverage cybersecurity program delivered by a single integrated team.
Product overview
DeepSeas is a cybersecurity company offering a unified platform-plus-services architecture. The portfolio comprises seven distinct but complementary services: Managed Detection and Response (24/7 monitoring and response), Offensive Security (ethical hacking and penetration testing), Threat Intelligence (proactive threat hunting), Governance Risk & Compliance (regulatory compliance support), CyberFusion SOC (dedicated security operations center), Strategic Security Advisory (C-suite guidance), and DeepSeas Complete (full-coverage bundled program). These services can be engaged individually or combined into a comprehensive cybersecurity program, with DeepSeas Complete serving as the umbrella offering that integrates all capabilities.
Differentiator
Problem solved
Functional benefit
Products and services
- Managed Detection and Response
- Offensive Security
- Threat Intelligence
- Governance Risk & Compliance
- CyberFusion SOC
- Strategic Security Advisory
- DeepSeas Complete
Companies that use GreyCastle Security
Customer profileNamed customers4 records
Segments3 records
Ideal customer profiles1 record
GreyCastle Security technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
AI capability1 record
Feature1 record
GreyCastle Security partnerships and signals
Strategic signalScale indicators1 record
Recent moves1 record
Expansion highlights3 records
GreyCastle Security competitors and assessment
Company assessmentDirect peers
- Arctic Wolf Networks: Arctic Wolf is a leading managed detection and response and security operations provider offering 24/7 monitoring, managed risk, and security awareness. It is a direct MSSP peer targeting similar mid-market and enterprise customers with a subscription MDR model.
- Expel: Expel provides managed detection and response services with transparent, technology-agnostic security operations. It directly competes in the MSSP space with similar customer profiles and a subscription-led delivery model.
- eSentire: eSentire is an MDR specialist delivering 24/7 threat hunting, detection, and response with Atlas XDR and Atlas SOC. It is a direct peer focused on managed security services for mid-market organizations.
- ReliaQuest: ReliaQuest offers a security operations platform combined with managed detection and response services (GreyMatter), competing head-on in the MSSP market with both technology and services.
- Huntress: Huntress provides managed detection and response focused on endpoints, identities, and Microsoft 365 for SMB and mid-market customers, serving as a direct subscription MDR peer.
- Critical Start: Critical Start delivers MDR services and a managed SIEM/XDR platform with analyst-led response. It is a direct competitor in the MSSP market for organizations seeking outsourced SOC capabilities.
Broad incumbents
- Sophos Managed Detection and Response: Sophos offers a broad cybersecurity portfolio including a fully managed MDR service that competes for the same customers as a turnkey 24/7 SOC offering. As an established vendor, it represents a larger incumbent alternative.
- CrowdStrike Falcon Complete: CrowdStrike is a key technology partner but also competes via Falcon Complete, its own fully managed MDR service. This creates a partner-competitor dynamic where CrowdStrike bundles endpoint detection with response services.
- Microsoft Defender Experts: Microsoft offers Defender Experts for XDR and Sentinel-based managed SOC services that compete directly for mid-market customers, while also being a key partner. This dual role mirrors the CrowdStrike dynamic.
Emerging players
- Blackpoint Cyber: Blackpoint Cyber provides managed detection and response focused on MSPs and their SMB customers, with a strong emphasis on rapid incident response. It is an emerging MSSP competitor with overlapping target customers in education and SMB.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat2 records
Key risks6 records
Key highlights6 records
Customer concentration
GreyCastle Security social profiles
Digital presenceGreyCastle Security compliance and trust
Trust signalCompliance2 records
GreyCastle Security financial estimates
Financial estimateRevenue estimate
Valuation estimate
GreyCastle Security leadership team
Management profileNumber of profiles
Profiles8 records
GreyCastle Security funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
GreyCastle Security M&A and investment
M&A and investmentM&A1 record
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about GreyCastle Security
What does GreyCastle Security do?
GreyCastle Security is a service provider dedicated exclusively to cybersecurity and the practical management of cybersecurity risks. The firm delivers managed detection and response, offensive security testing, threat intelligence, governance risk and compliance, a dedicated CyberFusion SOC, and strategic C-suite security advisory under unified programs. Customers can purchase individual services or a bundled full-coverage cybersecurity program delivered by a single integrated team.
When was GreyCastle Security founded?
GreyCastle Security was founded in 2011. It employs 11 to 50 people.
Where is GreyCastle Security based?
GreyCastle Security is headquartered in Troy, United States, in the North America region.
How does GreyCastle Security make money?
Two revenue lines are on record. Managed Security Services are the primary driver. The others are professional Security Services.
Who are GreyCastle Security's main competitors?
Direct peers on record are Arctic Wolf Networks, Expel, eSentire, ReliaQuest, Huntress and Critical Start. Broad incumbents are Sophos Managed Detection and Response, CrowdStrike Falcon Complete and Microsoft Defender Experts. Blackpoint Cyber is listed as an emerging player.
Does GreyCastle Security have an API?
No public API is recorded for GreyCastle Security.
What industry is GreyCastle Security in?
GreyCastle Security's product category is Cybersecurity Services. Its primary akta.pro industry code is BPAEADAG, Network Security Managed Services (Firewall/IDS/IPS/SASE), with a secondary code of BPAKAHAN, OT/ICS & Critical Infrastructure Cybersecurity Services. Its NAICS code is 5616 and its SIC code is 8700.