The insider threat in practice: How it happens and why it's so dangerous

While organizations fortify their perimeter defenses with cutting-edge technology, they often overlook the most significant cybersecurity vulnerability – the trusted employee who becomes compromised through illegal activities conducted on corporate devices.

Cybersecurity veteran Bob Lewis has witnessed this reality firsthand during his 40-year career, which has included work in the military, law enforcement, and financial institutions.

In this blog, Bob shares insights on how insider threats happen, why regular security tools can't catch them, and how attackers take advantage of these blind spots, even in organizations with strong defenses.

Insights from 40 years in cybersecurity

When it comes to understanding the true nature of cyber threats, few perspectives are as valuable as those from someone who's spent decades on the front lines. In 40 years of cybersecurity work, including with the Royal Air Force Police, National Crime Agency, and financial services, Bob has investigated nearly every type of digital crime imaginable.

The perfect insider vulnerability

The most dangerous threats don't need to break through sophisticated barriers – they're already inside with legitimate access, operating under the radar of conventional security systems.

"When you detect problematic material on an employee's device, you typically find much more than just that initial content. You'll often discover other questionable material, and quite frequently, malware and spyware are running in the background without anyone's knowledge."

This cascade of security vulnerabilities is what makes insider threats particularly dangerous. An individual engaging in high-risk personal activities doesn't simply create a policy violation – they create an entire attack surface that sophisticated adversaries can exploit.

How personal behavior becomes organizational vulnerability

The most concerning aspect isn't necessarily the malicious insider (though they exist). It's the trusted employee who becomes compromised through their actions. These vulnerabilities arise when employees use corporate devices to access illegal or extremely inappropriate content, where the consequences of discovery would be devastating both personally and professionally.

"When someone visits these dark websites, the operators capture their digital footprint – operating system, name, email, device identifiers, and IP address. With this information, they can find you on social media and build a complete profile. Suddenly, you're extremely vulnerable to blackmail and extortion."

This isn't theoretical – it's the reality of modern cybercrime. State-sponsored threat actors and sophisticated criminal organizations actively seek these vulnerabilities as recruitment opportunities.

They identify individuals not because of their importance to the organization, but because of personal behaviors that make them susceptible to coercion.

Why traditional security tools miss this

The problem is compounded by the fact that conventional security tools aren't designed to detect these high-risk behaviors.

"Most security is focused entirely on preventing intrusion, not on preventing exfiltration. When I ask security teams how they'd detect someone trying to break OUT of their network rather than into it, they're often at a loss. That's when they realize the value of specialized detection tools that can identify these internal vulnerabilities."

This blind spot exists because traditional security technologies excel at blocking unauthorized access but remain practically blind to high-risk activities happening within the perimeter. Security teams invest heavily in defending against external threats while overlooking the fact that their greatest vulnerability might already have legitimate access.

The perfect recruitment scenario

When someone is engaging in deeply personal, high-risk behavior, the threat of exposure creates what counterintelligence professionals call "the perfect recruitment scenario." These individuals aren't traditional spies – they're trapped by their own actions.

This vulnerability creates extraordinary leverage for threat actors. They don't need sophisticated technical attacks when they can simply compel an insider to:

• Hand over their trusted credentials
• Disable security controls
• Create backdoor access
• Exfiltrate sensitive data These actions bypass conventional security precisely because they involve legitimate users performing technically authorized functions, making them the most difficult threats to detect.

The scale of the challenge

Perhaps most concerning is how few organizations recognize this vulnerability. A persistent pattern of denial exists across organizations of all types, particularly regarding illegal content like child sexual abuse material (CSAM). The uncomfortable nature of this topic often leads to a "don't look, don't know" mentality that creates perfect conditions for exploitation.

"We've seen cases where individuals have been coerced into compromising their organizations because of these personal vulnerabilities. Police reports confirm that this type of blackmail happens more frequently than most security professionals realize."

This isn't an edge case. These vulnerabilities exist across every organization of sufficient size. When organizations fail to acknowledge this reality, they leave themselves exposed to one of the most potent attack vectors available to sophisticated adversaries.

Take a proactive approach

Forward-looking security leaders are already addressing this critical gap. Rather than relying solely on perimeter defense, they're implementing precise detection tools designed to identify these high-risk behaviors before they can be exploited.

"Understanding the risks posed by human behavior is the next frontier in cybersecurity. Organizations that recognize this threat are far better positioned to protect themselves against more sophisticated threats."