CTEM Explained: Making Sense of Ongoing Threat Assessments

The Evolution of Security: Understanding Continuous Threat Exposure Management

Point-in-time security assessments are no longer sufficient to protect against sophisticated cyber attacks. Organisations need a more dynamic, continuous approach to identifying and addressing security vulnerabilities. Continuous Threat Exposure Management (CTEM) has emerged as a strategic framework that enables organisations to stay ahead of emerging threats and maintain robust security postures.

What is CTEM and why does it matter?

Continuous Threat Exposure Management (CTEM) is a proactive, systematic approach to identifying, prioritising, and addressing potential security vulnerabilities across an organisation’s attack surface. Unlike traditional point-in-time security assessments, CTEM operates as an ongoing cycle that continuously evaluates security posture against evolving threats.

Traditional Assessments	CTEM Approach
Periodic (quarterly/annual)	Continuous
Point-in-time snapshots	Ongoing monitoring
Reactive approach	Proactive stance
Gap between assessments	No security visibility gaps

CTEM has become increasingly important because cyber threats are constantly changing. Attackers develop new techniques and exploit previously unknown vulnerabilities daily.

For organisations subject to regulatory frameworks like NIS2, DORA, and UK CSRA, CTEM provides a methodical approach to satisfying compliance requirements. These regulations specifically mandate ongoing validation of security controls and demonstration of cyber resilience—requirements that CTEM directly addresses through its continuous assessment methodology.

Beyond compliance, CTEM enables organisations to adopt a more proactive security stance, identifying and addressing vulnerabilities before they can be exploited. This security controls validation approach significantly reduces the risk of successful cyber attacks, including ransomware and data breaches.

The 5 stages of effective CTEM

Implementing CTEM involves a continuous cycle of five interconnected stages that work together to create a comprehensive security improvement process:

1. Scoping: Defining the boundaries of assessment, including critical assets, systems, and potential attack vectors. This involves identifying high-value targets that would be most attractive to attackers.
2. Discovery: Identifying potential vulnerabilities and exposures across the defined scope. This involves comprehensive scanning and assessment of infrastructure, applications, and configurations.
3. Prioritisation: Ranking identified vulnerabilities based on their potential impact, exploit likelihood, and business criticality. This ensures resources are directed toward addressing the most significant risks first.
4. Validation: Testing whether identified vulnerabilities can be exploited in the actual environment through safe, controlled simulations that mimic real-world attack techniques.
5. Mobilisation: Implementing remediation measures to address validated vulnerabilities and strengthen security posture.

These stages don’t follow a linear path but rather operate as a continuous loop. After mobilisation, the cycle begins again with scoping to account for changes in the environment and emergence of new threats. This continuous approach ensures security improvements are ongoing rather than periodic.

Common challenges in threat assessment

CTEM and the MITRE ATT&CK framework

The MITRE ATT&CK framework provides a comprehensive knowledge base of adversary tactics and techniques based on real-world observations. When integrated with CTEM, this framework transforms theoretical security concepts into practical, threat-informed defensive strategies.

By mapping security controls and validation efforts to the MITRE ATT&CK matrix, organisations gain valuable context about how effectively their defences address specific attack techniques used by real threat actors. This approach enables security teams to prioritise validation efforts based on the techniques most relevant to their industry and threat profile.

Implementing threat-informed defence through CTEM:

• Identifying the most relevant threat actors and attack techniques for your organisation
• Mapping existing security controls to MITRE ATT&CK techniques
• Identifying gaps where controls are missing or insufficient
• Continuously validating that controls effectively counter the mapped techniques

This structured approach ensures security investments directly address the most probable attack scenarios rather than theoretical vulnerabilities. Organisations can leverage platform solutions that integrate MITRE ATT&CK mappings into their validation processes.

How simulation reveals security weaknesses

Breach and Attack Simulation (BAS) is a cornerstone of effective CTEM programmes. These simulations safely replicate adversary behaviours without the disruption or risk associated with actual attacks. By executing controlled simulations, organisations can identify security gaps that might otherwise remain hidden until exploited by attackers.

The simulation approach focuses particularly on identifying misconfigurations in Windows, Linux, and Mac environments. These misconfigurations—such as excessive user privileges, weak password policies, or improperly secured network shares—often represent the path of least resistance for attackers.

Common misconfigurations revealed through simulation:

• Local administrator accounts have unnecessarily broad permissions
• Security settings intended to prevent credential theft are misconfigured
• Endpoint protection solutions have exceptions that create exploitation opportunities

Unlike vulnerability scanning, which primarily identifies missing patches, simulation-based testing evaluates the actual effectiveness of security controls against specific attack techniques. This provides a more accurate picture of security posture and helps organisations prioritise remediation efforts based on exploitability rather than theoretical vulnerability.

Implementing CTEM on limited resources

Strategy	Implementation Approach
Prioritisation	Focus validation efforts on the most critical assets and the most likely attack vectors first—internet-facing applications, systems storing sensitive data, or infrastructure supporting core business functions.
Automation	Leverage platforms that automate many aspects of the assessment process, from discovery to validation and reporting, allowing small teams to achieve broader coverage with less manual effort.
Phased approach	Start with a limited scope focused on the highest-risk areas, then gradually expand coverage as processes mature and efficiencies are realised.
Tool consolidation	Consolidate to platforms that offer multiple capabilities to reduce both costs and complexity of managing numerous security solutions.

Measuring the ROI of ongoing assessments

Demonstrating the business value of CTEM programmes requires metrics that connect security improvements to business outcomes:

By maintaining a continuous assessment and improvement cycle, organisations not only reduce their risk of cyber attacks but also optimise their security investments to deliver maximum protection where it matters most.

If you’re interested in learning more, contact our expert team today.