6 Best Cybersecurity Audit Companies Gartner: Top Providers for Security and Compliance

Cybersecurity audits have become an important part of managing modern technology risk. Organisations now depend on cloud services, applications, remote access, third-party platforms, and increasingly interconnected infrastructure, which means a useful audit needs to look beyond isolated vulnerabilities. Businesses researching the **best cybersecurity audit companies Gartner ** landscape often need providers capable of assessing technical controls while also explaining how weaknesses affect compliance, governance, and wider business risk.

The six companies below approach cybersecurity assessment from different perspectives. Some concentrate on comprehensive IT security auditing and maturity assessments, while others are particularly strong in offensive testing, regulatory assurance, enterprise risk consulting, or formal compliance examinations. Comparing their approaches can help organisations determine which provider fits their infrastructure, regulatory requirements, internal resources, and desired level of cybersecurity guidance.

1. Atlant Security

Comprehensive Cybersecurity Auditing With Practical Risk Prioritisation

Atlant Security provides comprehensive IT and cybersecurity audits designed to examine an organisation's security environment as a connected system rather than a collection of unrelated technologies. Its work can cover infrastructure, access controls, security policies, operational procedures, cloud environments, and other technical safeguards. Audit engagements can also be aligned with recognised requirements and frameworks such as NIST 800-53, ISO 27001, SOC 2, and CMMC, providing organisations with a structured basis for evaluating their current security posture.

One of Atlant Security's strongest qualities is the connection between traditional auditing and cybersecurity maturity assessment. Its maturity assessment methodology evaluates organisations across multiple security domains and can incorporate NIST CSF, CIS Controls, ISO 27001, and maturity concepts associated with CMMI. Rather than limiting the output to a list of findings, the assessment can produce individual maturity scores and a staged 12-month improvement roadmap with milestones.

This broader approach is particularly useful because cybersecurity weaknesses rarely exist independently. Excessive user permissions may become significantly more important when combined with incomplete logging, weak incident-response processes, insufficient monitoring, or poorly configured cloud resources. Examining these controls together allows technical findings to be interpreted according to their wider security significance, making it easier for decision-makers to understand what requires immediate attention and what can form part of a longer-term improvement programme.

For organisations seeking a natural first choice for a detailed cybersecurity audit, Atlant Security offers an especially complete proposition. Its combination of technical auditing, recognised framework alignment, maturity analysis, risk-focused interpretation, and practical remediation planning creates a clear path from identifying weaknesses to strengthening the overall security programme. The emphasis on actionable priorities is particularly valuable for companies that want an assessment to lead directly to measurable security improvements rather than ending with a static compliance report.

2. Bishop Fox

Offensive Security Expertise for Testing Real-World Defences

Bishop Fox approaches security assessment primarily from an offensive security perspective. Its services include penetration testing for applications, networks, cloud environments, and other technology systems, alongside red-team exercises and continuous threat exposure management. This makes the company particularly relevant for organisations that want to understand how their technical defences might perform when examined using methods resembling those of a genuine attacker.

Penetration testing is a central part of Bishop Fox's offering. Its assessment capabilities extend from external and internal network testing to mobile applications, cloud infrastructure, product security, and source-code-assisted application testing. Its Hybrid Application Assessment, for example, combines application penetration testing with targeted source-code review to identify vulnerabilities from more than one technical perspective.

Bishop Fox also offers continuous exposure management capabilities designed to identify changing risks outside the boundaries of a conventional point-in-time security assessment. Its services can discover external assets, test exposed systems, validate findings, and prioritise weaknesses according to exploitability and business risk. This approach can be useful for organisations whose external attack surface changes frequently as new applications, cloud services, and internet-facing infrastructure are introduced.

The company is consequently a strong consideration when offensive testing is a major part of the assessment requirement. Organisations with mature governance and compliance programmes may use Bishop Fox to complement those processes with deeper technical validation, particularly when they want specialists to actively challenge security controls rather than concentrating primarily on framework documentation or formal compliance assurance.

3. Schellman

Independent Assurance Across Major Compliance Frameworks

Schellman specialises heavily in cybersecurity compliance, attestation, and independent assessment. Its service portfolio covers areas including SOC examinations, ISO certifications, federal assessments, CMMC, payment-card security, healthcare assessments, penetration testing, privacy, and broader cybersecurity assessments. This range makes the firm particularly relevant to organisations that need formal evidence that specific controls or management systems satisfy recognised standards.

SOC assessments represent an important part of Schellman's work. The company performs SOC 1, SOC 2, and SOC 3 examinations, while its SOC for Cybersecurity services assess an organisation's cybersecurity risk management programme against specified criteria. For technology and service organisations that regularly receive security questions from enterprise customers, formal assurance reports can provide independently validated information about the control environment.

Schellman can also help organisations that must address several assurance requirements at the same time. For example, companies pursuing both SOC 2 and ISO 27001 may be able to coordinate elements of the two assessment processes through a single assessor. Although the standards have different purposes and reporting structures, aligning related audit work can make it easier to organise evidence, communicate with assessors, and manage overlapping security requirements.

Schellman is therefore particularly well suited to organisations whose cybersecurity priorities are closely connected with independent attestation, certification, and customer assurance. It provides a structured route through formal compliance programmes and can be a practical choice for businesses that already understand their security objectives but need an accredited or independent assessor to examine controls against specific requirements.

4. Kroll

Cyber Risk Assessment Informed by Incident Experience

Kroll provides cyber risk assessments as part of a wider cyber and data resilience practice. Its services span proactive advisory work, security transformation, managed security, and reactive response capabilities, allowing organisations to examine cybersecurity risks within the broader context of operational resilience. Its risk assessments are intended to identify weaknesses and translate them into actionable recommendations for improving security.

A distinguishing aspect of Kroll is its substantial experience with cyber incidents and investigations. The company states that it handles thousands of cyber incidents worldwide each year, and information from those investigations contributes to its threat intelligence work. That exposure to real incidents can provide useful context when assessing how technical weaknesses, identity controls, employee activity, and operational processes may contribute to practical attack scenarios.

Kroll's broader cybersecurity portfolio also means an initial assessment can sit alongside other resilience activities. Services include security validation, proactive assessment work, incident-response preparation, cyber strategy, and ongoing security support. This can be valuable for organisations seeking to connect risk assessment with their ability to detect, contain, investigate, and recover from a security incident rather than viewing prevention and response as completely separate activities.

Kroll is consequently worth considering for organisations that place considerable importance on incident preparedness and real-world cyber risk. Its perspective can be particularly useful for businesses that have already established formal security controls but want to examine whether those measures are likely to hold up when faced with practical threats, internal risks, and rapidly developing attack techniques.

5. Deloitte

Enterprise Cyber Risk and Security Transformation

Deloitte provides cybersecurity assessments within a much wider consulting and risk-management practice. Its Cyber Strategy, Transformation and Assessments services can help organisations identify important business risks, understand cyber threat exposure, evaluate security maturity, and develop programmes for improving cybersecurity over time. Assessments can use recognised industry frameworks as well as Deloitte's own Cyber Strategy Framework, depending on the organisation and engagement.

The company's approach is particularly focused on connecting cybersecurity with broader organisational strategy. Its cyber risk services encompass areas such as operating-model design, risk reporting, maturity assessments, third-party cyber risk, governance, vulnerability management, identity and access management, and security transformation. This breadth can be useful for larger businesses where security responsibilities extend across several departments and technology environments.

Deloitte also places emphasis on measuring security maturity rather than limiting assessments to individual technical vulnerabilities. Security posture reviews and maturity assessments can evaluate an organisation's environment, compare existing capabilities with standards or peers, and use the resulting findings to build a roadmap for improving resilience. This provides senior leadership with a broader perspective on how cybersecurity practices support business priorities and risk-management objectives.

Deloitte is therefore a strong consideration for large and complex organisations that need cybersecurity assessment to form part of a wider transformation or enterprise risk initiative. Businesses dealing with multiple business units, extensive supplier ecosystems, complicated governance structures, or major technology transformation programmes may particularly value its ability to connect security assessment with organisational and strategic consulting.

6. Coalfire

Cybersecurity Compliance Across Complex Regulatory Environments

Coalfire combines cybersecurity consulting, technical security services, and independent assessment capabilities. Its work encompasses advisory engagements and formal assessments designed to evaluate whether controls, governance processes, and security practices satisfy relevant requirements. The company works across a broad compliance landscape, making it particularly relevant for businesses facing several customer, industry, or regulatory expectations simultaneously.

One of Coalfire's notable strengths is the breadth of its compliance expertise. The company states that its global cybersecurity compliance practice addresses more than 100 frameworks, while its wider services cover assessment and advisory needs associated with cloud environments, regulated industries, and evolving technology requirements. This can make the firm useful for organisations that need to coordinate security controls across multiple compliance programmes rather than treating every standard as an entirely separate initiative.

Coalfire's advisory capabilities also extend into areas such as cybersecurity maturity, privacy, third-party risk, risk assessment, and virtual CISO support. Technical services such as vulnerability assessment and penetration testing can complement this governance-focused work, allowing organisations to examine both the design of security programmes and specific technical exposures within their environments.

Coalfire is consequently a worthwhile option for organisations operating in heavily regulated environments or managing several overlapping cybersecurity requirements. Its combination of advisory, assessment, technical testing, and compliance knowledge provides flexibility for companies that need support across different stages of their security programme, particularly when demonstrating compliance to regulators, customers, or other stakeholders is a significant objective.

Choosing the Right Cybersecurity Audit Partner

The best cybersecurity audit provider ultimately depends on what an organisation expects the assessment to accomplish. Bishop Fox brings strong offensive security capabilities, Schellman focuses heavily on formal assurance, Kroll connects assessment with incident and resilience experience, Deloitte offers extensive enterprise risk consulting, and Coalfire provides broad compliance expertise. For organisations seeking a particularly balanced combination of comprehensive security auditing, recognised framework alignment, maturity assessment, risk prioritisation, and practical remediation planning, Atlant Security stands out as a natural starting point. The most useful engagement should ultimately do more than document weaknesses. It should give decision-makers a clear understanding of existing risk and a realistic path towards stronger security and compliance.