When the threat comes from within

Organisations often focus on external threats, yet some of the most significant and persistent risks come from within. Insider threats exploit the very trust, access, and knowledge that employees and contractors hold by virtue of their roles. 

Employees who understand the company’s systems, processes, and culture have the potential, whether intentionally or accidentally, to create vulnerabilities that can be exploited. The challenge lies in the fact that insiders already have legitimate access, meaning traditional security measures offer little protection against their actions. 

Understanding Insider Threats 

Insider threats can take many forms: 

• Malicious insiders exploit their access intentionally for personal, financial, or ideological gain. This might include theft of intellectual property, sabotage of systems, or leaking sensitive information. Malicious insiders are often the hardest to detect because they understand organisational processes and know how to avoid conventional security measures. 
• Negligent insiders inadvertently create vulnerabilities. They may bypass procedures due to convenience, lack of awareness, or operational pressure. Though unintentional, their actions can have consequences as severe as deliberate attacks, particularly when they involve sensitive systems or data. 
• Compromised insiders are coerced, manipulated, or socially engineered by external actors. These individuals may have no malicious intent but can become vectors for external threats, effectively bridging insider knowledge with outside motives. 

The human factor  

Insider threats are unique because they exploit human behaviour. Research shows that insider incidents often correlate with organisational stressors, such as tight deadlines, high-pressure environments, or perceived unfair treatment. Employees under pressure may bypass procedures or make mistakes, inadvertently creating vulnerabilities. Similarly, a disengaged employee with privileged access can become a risk vector, even without malicious intent. 

Senior security leaders must therefore view insider threat management through a human lens, considering motivation, behaviour, and opportunity alongside technical controls. 

A converged approach 

Effectively managing insider risk requires a converged security strategy that integrates people, cyber, and physical measures. Senior security leaders must approach this threat as multi-dimensional, recognising that vulnerabilities often span multiple domains: 

• People – Behavioural monitoring, security awareness, and culture are key. Employees must understand their role in protecting the organisations sensitive assets, and organisations must create a culture where employees feel comfortable raising any concerns.  
• Cyber – Insider attacks often exploit privileged access. Controls such as role-based access, segmentation, audit trails, and continuous monitoring are essential. Detection must go beyond simple rule-based alerts to incorporate anomaly detection and behavioural analytics. 
• Physical – Secure access to facilities, asset control, and monitoring of sensitive areas are equally critical. Insider risks may manifest as unauthorised access to secure rooms or manipulation of critical infrastructure. 

The role of Due Diligence

Preventing insider threats begins before access is granted. Due diligence is a foundational element of insider threat management. 

Due diligence needs to be addressed as more than a procedural formality; it is a deep, investigative process that examines financial stability, criminal history, behavioural patterns, and other indicators of potential risk. It helps organisations identify vulnerabilities in individuals before they can create harm. 

Key aspects of due diligence include: 

• Verifying credentials, qualifications, and employment history. 
• Assessing financial and behavioural indicators that could make someone susceptible to coercion or corruption. 
• Understanding past incidents or behaviours that may signal risk. 

Importantly, due diligence should not stop at onboarding. Continuous reassessment and monitoring are necessary to adapt to changing circumstances, ensuring that access privileges and responsibilities remain aligned with the individual’s risk profile. 

Detection, Investigation, and Protection 

Senior security teams should think of insider threat management as a continuous lifecycle: 

• Detect – Identify anomalies and warning signs across cyber, physical, and people domains. This includes monitoring system access patterns, observing workplace behaviour, and conducting periodic risk assessments. 
• Investigate – Apply structured, evidence-based processes to confirm potential threats without compromising employee trust or operational continuity.  
• Prevent – Reduce opportunity and motivation through access controls, policy design, and employee engagement. Security measures must be practical and aligned with operational realities to avoid workarounds. 
• Protect – Limit impact when incidents occur, ensuring that critical systems, assets, and data are safeguarded. Implement layered controls, rapid response protocols, and clear reporting channels. 
• Build and Improve – Continuously refine processes, tools, and training to stay ahead of evolving threats. Capture lessons learned from incidents and assessments, and embed improvements into policies, awareness programmes, and operational practices.  

Cultural considerations 

As highlighted in a previous blog on security culture (link), systems must be designed to work for people. Overly complex or irrational procedures encourage workarounds and disengagement. By involving employees in security initiatives through security champions, awareness campaigns, and practical training and testing (link) organisations can create a culture of accountability and vigilance. 

Insider threat management is closely connected to security culture. Organisations with engaged, informed employees are far better positioned to detect, prevent, and respond to the full range of insider risks, whether malicious, negligent, or compromised. The people within the organisation are not just part of the solution; they are the first and most critical line of defence. 

Why insider threats require attention 

Insider threats are unique because they exploit trust and access. Organisations cannot rely solely on technology or policies they must consider behaviour, motivation, and opportunity. Even minor disengagement or lack of awareness can create exploitable gaps. 

By combining due diligence, proactive detection and prevention, thorough investigation, and ongoing improvement, organisations can significantly reduce the likelihood and impact of insider incidents. 

Insider threats may never be eliminated entirely, but a structured, thoughtful approach ensures that risk is understood, monitored, and mitigated effectively.