What Are Insider Threats & How to Detect Them

Businesses spend a fortune to fight back against external threats, yet one of the most damaging cybersecurity risks is already inside the building. These are insider threats—security risks originating from the very people you trust with access to your network: your employees, contractors, and partners.

This isn’t a rare occurrence but a consistent and growing trend. According to recent studies, a significant 76% of organizations have seen a rise in insider threat activity over the past five years, with many reporting a dramatic increase in the number of incidents annually.

An insider threat happens when someone with authorized access to company systems and sensitive data misuses that privilege. The motivation can be malicious, like a disgruntled ex-employee seeking revenge, or purely accidental, such as a well-meaning team member who unknowingly falls for a phishing scam. Whether the act is intentional or not, the result is the same: your organization’s critical data, intellectual property, and reputation are put at risk.

Who is an Insider? 

In the context of cybersecurity, an insider is anyone who has or previously had authorized access to your organization’s data, systems, or physical locations. This broad definition covers a wide range of roles and relationships, each with a different level of access and potential risk:

• Employees: Full-time, part-time, or temporary staff with access to company resources. An example would be a sales manager accessing the company CRM or a marketing specialist with access to customer lists.
• Former employees: Individuals who have left the company but whose access credentials were not fully or immediately revoked. An example would be a software developer who left on bad terms and discovers their login to the company’s code repository still works.
• Contractors & consultants: Third-party individuals hired for specific projects that hold limited authorized access. An example would be a freelance graphic designer granted temporary access to your company’s digital asset management platform.
• Third-party vendors: Companies that provide critical services and often require integrated system access. An example would be managed IT service provider with administrative privileges to your network or a payroll company that handles sensitive employee financial data.
• Business partners: Trusted entities in a formal business relationship who share sensitive information. An example would be a partner in a joint venture who has access to shared financial projections and strategic plans.
• Privileged users: Individuals with high-level or administrative access to critical systems, often called “super users.” They can also be known as managerial insider threats. An example would be a network administrator who can modify security settings or a database admin with access to all customer records.

Essentially, anyone you have trusted with legitimate, “behind-the-scenes” access can be considered an insider. While this trust is necessary for business operations, each of these roles also represents a potential point of risk, whether the threat that emerges is intentional or purely accidental.

Why Are Insider Threats Difficult to Detect?

Insider threats are notoriously difficult to detect and combat. Unlike external attacks that must breach a perimeter, these security threats operate from within the organization’s trusted boundaries. The problem is not only widespread but growing at an alarming rate.

According to the 2024 report from Cybersecurity Insiders, a staggering 83% of organizations experienced at least one insider attack in the last year. The report also revealed a fivefold increase in the frequency of attacks for many organizations, highlighting that this is an escalating challenge for security leaders.

This difficulty arises from a few core factors that make insider activity blend in with routine, everyday operations.

• Most security tools focus on external threats: Traditional cybersecurity solutions are designed to identify and block external cyber threats. They are not inherently built to scrutinize the actions of legitimate users. An insider using their own valid credentials doesn’t trigger the same alarms as an external hacker, and traditional threat intelligence feeds are geared toward known external malware, not internal user behavior.
• Insiders have a knowledge advantage: An employee or contractor already knows the organization’s network, security policies, and procedures. They often know precisely where valuable data is stored and what normal data access patterns look like, allowing them to mask their activities within standard business workflows.
• The ambiguity of intent: A single action can be difficult to classify without broader context. For example, an employee downloading a large report could be doing their job, making an honest mistake, or preparing to exfiltrate data. The initial digital footprint looks identical in all three scenarios. Distinguishing between malicious intent, simple negligence, and normal job functions is a central challenge for any insider threat detection program.

Types of Insider Threats

Insider threats can be categorized in several ways based on the intent and impact they have on an organization. The following are some of the most common types of insider threats: 

• Malicious insider threats
• Negligent insider threats
• Compromised insiders
• Opportunistic insiders

Malicious Insiders (Intentional Threats) 

Malicious insider threats are intentional, meaning these individuals deliberately harm the organization. But what is the motivation behind these malicious insider threats? Individuals that abuse their privileged access typically cause damages due to personal grievances or self-serving reasons such as:

• Financial gain: Selling company trade secrets or sensitive data to competitors for personal profit.  
• Retribution: Seeking to harm the company due to perceived mistreatment, job loss, feeling undervalued, or being passed over for promotions.  
• Personal vendettas: Pursuing revenge against a manager, colleague, or the organization for any personal reason. 
• Ideological beliefs: Acting out based on personal beliefs or political convictions that oppose the organization.  
• Espionage: Working undercover as a spy for a competitor, foreign government, or other entity.  
• Blackmail or coercion: Experiencing pressure from external parties to unlawfully obtain information.

Negligent Insiders (Unintentional Threats) 

Negligent insiders unintentionally cause harm, typically due to carelessness, lack of awareness, or failure to follow security procedures. While there is no malicious intent, these individuals may inadvertently: 

• Leak data: Sending sensitive information to the wrong recipient or leaving it unsecured (i.e. not locking the computer when walking away from their desk).   
• Fall victim to phishing: Clicking on harmful links or opening infected attachments can compromise their account and potentially the entire network.
• Fail to follow security protocols: Ignoring security policies or best practices may lead to vulnerabilities that can be taken advantage of.   

Compromised Insiders

A compromised insider refers to an employee, contractor, or other authorized user whose account, credentials, or device has been hijacked by an external attacker. This situation may arise from phishing, malware, credential theft, or other manipulation tactics—allowing the attacker access to sensitive systems and data. 

This type of threat can be difficult to identify since the attackers utilize legitimate insider credentials to access the network. This allows external cybercriminals to steal data and inflict harm, while the insider may be completely unaware of the compromise. 

Opportunistic Insiders

Opportunistic insiders misuse their access to an organization’s systems or information for their own personal benefit. They may be employees, contractors, or third-party users that take advantage of weak security controls. 

While their initial intent may not be harmful, opportunistic insiders pose a growing threat, as they seize unexpected opportunities when they present themselves. These individuals may inadvertently stumble across sensitive data and frequently exploit it without prior planning.  

It’s important to note that the above categories of insiders aren’t always mutually exclusive. For example, a negligent insider could transition into a compromised insider if their account is removed following a phishing incident. Understanding the distinctions between the different types of insider threats enables organizations to develop more efficient prevention and detection measures. 

Insider Risk vs Insider Threat

Let’s examine the differences between an insider risk and an insider threat. In simple terms, insider risk is a broader concept that includes unintentionally compromised data, while an insider threat is when someone deliberately harms an organization. 

Insider Risk (Not Yet a Threat)

Insider risk encompasses any potential negative impact within an organization—resulting from actions taken by individuals who possess authorized access. This includes both malicious actions (insider threats) and inadvertent actions that could result in damage. Essentially, it’s the possibility or likelihood of something going wrong due to an insider.

Insider Threat (Active Risk in Progress)

An insider threat is a subset of insider risk that refers to malicious or intentional actions taken by an insider with the intent of harming the organization. This could include data theft, security breaches, or system sabotage. Effectively, it’s an active intent to cause damage.

While all insider threats originate from insider risks, not all insider risks become threats. For example, an employee accidentally clicking on a phishing link represents an insider risk—potentially jeopardizing the organization’s network. However, that employee does not necessarily constitute an insider threat unless there was a deliberate intention to harm the company. 

How Does an Insider Threat Occur?

An insider threat occurs when an individual who has been granted authorized access to an organization’s systems, data, or facilities exploits that access, whether intentionally or unintentionally. This can lead to security breaches, data leaks, or disruptions in operations. 

Insider threats can happen due to negligence, malicious intent, or external compromise. The following are nine of the most common ways that threats can occur from the inside: 

1. Exploitation of legitimate access: Individuals with insider status have authorized access to systems and data—making it easier to misuse that privilege. They don’t need to “break in” in the traditional sense but rather utilize their credentials to exploit the system. 
2. Social engineering: Individuals within an organization may be influenced by colleagues or business partners to divulge confidential information or engage in activities that jeopardize security. This type of manipulation involves psychological tactics such as phishing, creating fabricated scenarios, or building trust to gain access. 
3. Data exfiltration: This occurs when individuals transfer data to removable storage devices such as USB drives or external hard drives. They then email the data to personal accounts, upload it to cloud storage platforms, or print it out.
4. System manipulation: Insiders with certain privileges can modify system settings, disable security controls, or even install malware. This can lead to vulnerabilities such as additional exploitation or data breaches. 
5. Physical access: Insiders with onsite access to facilities can steal equipment, tamper with hardware, or gain access to restricted areas.  
6. Account compromise: While their intentions may not be malicious, an insider’s account can be compromised by external attackers through phishing, malware, or password cracking. In this scenario, the attackers use the insider’s credentials to execute harmful actions.
7. Negligence and carelessness: Unintentional insider threats may arise from human mistakes, such as accidentally sending sensitive information to the wrong recipient, falling victim to a phishing scam, or failing to follow security protocols.
8. Gradual escalation of privileges: While an insider might start with limited access, they may gradually gain more privileges over time, eventually reaching an access level that enables them to cause significant damage.  
9. Departing employees: Employees who are on their way out the door, especially those who are disgruntled, may be more likely to steal data, sabotage systems, or maintain access to company resources after their employment ends.

Insider Threat Indicators and Patterns 

Effective insider threat detection requires recognizing early warning signs and identifying patterns associated with risky behavior before the onset of security incidents. Such threats frequently have behavioral, digital, and operational indicators that organizations can observe through user activity monitoring, behavioral analytics, and security tools.

Behavior Patterns

Patterns or changes in an insider’s behavior, such as working odd hours or accessing company systems remotely, may serve as red flags. While there may not be proof of malicious intent, these patterns should be identified and monitored. 

Insider threats frequently display specific behavioral patterns before any malicious or negligent acts are committed. Organizations can better mitigate data breaches, fraud, and system sabotage by recognizing these patterns early on. The following are key behavior categories and their associated risk indicators: 

• Extended working hours or atypical work schedules: Working late night shifts, weekends, or operating during odd hours, especially if it coincides with access to sensitive data or systems, may suggest efforts to obtain information beyond routine monitoring.
• Accessing information unrelated to job responsibilities: Viewing, downloading, or printing documents irrelevant to an individual’s role may suggest a potential intent to misuse data.
• Deviations from usual behavior: Sudden changes in personality, such as irritability, defensiveness, or social withdrawal, may be associated with stress stemming from participation in illicit activities.
• Disgruntled or negative attitude: Expressing dissatisfaction with the organization, leadership, or job duties may motivate revenge or sabotage.
• Ignoring security policies: Consistently disregarding security procedures or best practices could indicate a lack of respect for rules or an attempt to bypass security measures.
• Bringing personal devices to secure areas: Introducing unauthorized personal devices into restricted areas may lead to data theft or other harmful activities. 

Technical Indicators

Insider threats often leave digital footprints or a trail of online data (think breadcrumbs) that can be identified through technical monitoring, anomaly detection, and security analytics. These indicators typically encompass unauthorized access, data exfiltration, system manipulation, and security breaches. 

These patterns pertain to an insider’s digital behaviors and interactions with systems and data and provide more concrete evidence of potential insider threats. Examples include:

• Unusual data access patterns: Accessing sensitive information outside of standard working hours, from unusual locations, or in high quantities might suggest potential data theft or unauthorized access.
• Data exfiltration efforts: Transferring large files to portable storage devices, emailing sensitive information to personal accounts, or uploading data to cloud storage services.
• Use of unauthorized software or devices: Installing unapproved software or connecting personal devices to the company network could introduce malware or create security vulnerabilities.
• Attempts to disable security controls: Efforts to disable antivirus software, firewall settings, or other security measures.
• Keyword searches related to data theft or sabotage: Searching for information on subjects such as “how to delete data securely” or “how to sell stolen data.”
• Utilizing anonymizing tools: Employing VPNs, the Tor browser, or other tools to conceal online activity.
• Modifications to system configurations: Adjusting system settings or access controls to obtain additional privileges or hide activities.
• Increased network activity: Unexplained surges in network traffic could indicate data exfiltration or other malicious activity.
• Creation of backdoors: Creating hidden entry points into systems or data to be utilized for future exploitation.
• Deletion of logs or audit trails: Attempting to erase records of any activities to cover one’s tracks.

It’s essential to recognize that no single indicator can definitively confirm the presence of an insider threat. However, further investigation is warranted when multiple behavioral and technical indicators are observed together. A comprehensive insider threat program should prioritize detecting and responding to these patterns to reduce potential risks.

Who Is at Risk of Insider Threats?

Every organization, regardless of size or industry, is susceptible to insider threats. However, specific sectors that handle highly sensitive or classified data are at a significantly higher risk of experiencing devastating consequences, such as substantial financial penalties, brand damage, and operational disruption. 

The type of data at risk may include intellectual property, trade secrets, customer information, employee data, financial records, and more. The loss of such data can result in competitive disadvantages, financial losses, reputational harm, and potential legal consequences.

While no organization is immune to insider threats, specific industries are statistically more vulnerable due to the nature of the information they handle. These high-risk sectors often include:

• Financial Services & Banking: This sector holds vast amounts of financial data, including customer account details, transaction records, and investment strategies— making it a prime target for insiders motivated by financial gain.
• Healthcare & Pharmaceuticals: Healthcare institutions maintain confidential patient data, such as medical records, insurance information, and personal details—making them susceptible to data breaches and regulatory penalties.
• Government & Defense: Government agencies hold classified information, national security secrets, and sensitive personal data—making them high-value targets for espionage and sabotage.
• Technology & SaaS: Organizations in the tech sector often possess intellectual property, trade secrets, and other proprietary information, which can be quite appealing to competitors or foreign entities.
• Telecommunications: Telecom companies have access to large amounts of customer data, such as call records and browsing history, making them susceptible to privacy breaches.
• Manufacturing: This industry holds a vast amount of intellectual property related to product design and manufacturing, which can be highly attractive to competitors.
• Energy, Utilities & Critical Infrastructure: This sector possesses access to coveted industrial control systems and operational technology—making them vulnerable to ransomware attacks and other threats. 

It’s important to recognize that while specific industries face a greater risk, any organization can be susceptible to insider threats. Thus, having a comprehensive security framework in place is crucial. 

How to Protect Against Insider Attacks

Preventing insider threats requires a thorough and multifaceted approach to security, combining protective measures, strong policies, and a robust security culture. Here’s a breakdown of key strategies:

Access Control and Least Privilege

• Principle of least privilege: Provide users only the minimum permissions and access rights needed to perform their job duties. This approach minimizes potential insider harm, even if they have been compromised. 
• Role-based access control (RBAC): A best practice is to assign access solely based on job roles and responsibilities which streamlines access management and ensures consistency.
• Multi-factor authentication (MFA): Require multiple authentication methods (e.g. passwords, security tokens, and biometrics) to verify user identity—making it harder for unauthorized access.

Monitoring and Detection

• User and entity behavior analytics (UEBA): Identify baselines for normal user activity and use machine learning to detect any irregular behavior that could be malicious.
• Security information and event management (SIEM): Collect and analyze security logs from multiple sources to help identify any unusual patterns or potential threats.
• Data loss prevention (DLP): Implement tools to ensure sensitive data doesn’t leave the organization’s control, whether intentionally or unintentionally.
• Endpoint Detection and Response (EDR): Monitor all endpoint devices, including laptops, desktops, and mobile devices for signs of malicious activity—enabling you to address threats as they arise.

Policies and Procedures

• Data handling policies: Establish clear protocols for handling sensitive data, such as storage, access, and disposal.
• Acceptable use policies: Define guidelines for the appropriate use of company resources (e.g. computers, networks, and internet access). 
• Incident response plan: Develop a communication plan highlighting how to respond to and recover from an insider threat.
• Background checks: Conduct thorough background checks for all new hires, particularly those with access to sensitive information.
• Employee offboarding procedures: Develop a process for promptly terminating system access and monitoring the activities of users who are leaving the organization.

Security Awareness Training

• Regular training: Provide regular security awareness training to employees, stressing the importance of data security and how to identify and report any suspicious activity. 
• Phishing awareness: Educate employees on how to recognize and avoid phishing scams, a common way attackers gain access to accounts on the inside.
• Social engineering awareness: Train employees on social engineering tactics and instruct them on how to avoid being manipulated into sharing sensitive information.

Physical Security

• Access control: Restrict physical access to sensitive areas and data centers.
• Surveillance systems: Use surveillance cameras and other security measures to monitor physical access.
• Visitor management: Implement a system for tracking and managing visitors.

Insider Threat Program

• Dedicated team: Form a specialized team responsible for managing insider threats.
• Risk assessment: Conduct regular risk assessments to detect any weaknesses and prioritize mitigation efforts.
• Collaboration: Encourage collaboration between security, HR, legal, and other relevant departments to effectively address insider threats. 

Data Security

• Data encryption: Safeguard sensitive data both in transit and at rest.
• Data backup and recovery: Create backups of critical data and have a plan for restoration in the case of a data breach.
• Data governance: Establish data governance policies to ensure its quality, integrity, and availability. 

What Is Not Considered an Insider Threat?

An insider threat is not to be confused with an attack from an external or unknown source. It’s important to understand what doesn’t constitute an insider threat to avoid incorrect labeling and misguided security efforts. The following seven situations are generally not considered insider threats: 

1. External attacks: Cyberattacks that originate from outside the organization, such as hacking attempts, malware infections, or disruption attacks, are not insider threats, but rather traditional cybersecurity threats.
2. Customer actions: Actions taken by external customers, regardless of how they affect the organization (e.g. fraudulent transactions and account takeovers), are not considered insider threats.  
3. Publicly available information leaks: If information is leaked due to a breach of a publicly accessible database, this is not an insider threat. The leak’s origin must be traced back to an insider with authorized access.
4. Third-party breaches: If a third-party vendor experiences a data breach and the organization is compromised, this is not an insider threat.
5. Unintentional data loss without malice: Accidental data loss due to negligence is not considered a malicious insider threat if no intent exists to inflict harm.
6. Former employees with no remaining access: Once a former employee’s access has been revoked, any actions they take become an external threat, not an insider threat. 
7. Isolated policy violations: While simple breaches of policy such as inappropriate web browsing or using personal devices on company Wi-Fi are violations, they are not considered insider threats.

The primary distinction is that an insider threat applies to an individual with legitimate access and misuses it, whether deliberately or inadvertently. On the flip side, if individuals do not possess authorized access, their actions won’t qualify as insider threats.

Insider Threat Examples

Insider threats can, without a doubt, be catastrophic for organizations, leading to data breaches, financial losses, and reputational damage. Below are real-life examples from various industries that demonstrate the risks associated with insider threats:

Rippling

Rippling sued its competitor Deel, in March 2025, accusing them of planting an employee spy within their organization. The lawsuit alleges that an individual hired by Rippling in 2023 as a Global Payroll Compliance Manager was acting as a mole for Deel.

Using their legitimate employee access over a period of four months, this alleged insider reportedly exfiltrated highly sensitive data from platforms like Salesforce, Google Drive, and Slack. The stolen information included customer lists, pricing strategies, competitive intelligence, and internal employee data, with the activity going undetected for months.

Tesla

In 2023, two former Tesla employees illegally accessed and leaked confidential information to the media. The data breach exposed trade secrets and employee data, as reported by the German newspaper “Handelsblatt”. This incident demonstrates not only a loss of intellectual property but also the potential for reputational damage due to insiders motivated by personal gain. 

Pegasus Airlines

In 2022, Pegasus Airlines experienced a data breach after an airline employee misconfigured security settings for an Amazon Web Services (AWS) storage bucket—exposing millions of files containing sensitive operational and personal data. This incident was attributed to employee negligence and highlights the importance of having proper security practices in place for all systems. 

CashApp

In 2021, a former CashApp employee accessed and leaked customer data, including brokerage account numbers and stock trading activity. The individual who caused the data breach was motivated by revenge following the termination of their employment. This scenario highlights the importance of managing employee access and continuous monitoring. 

General Electric

In 2020, a GE engineer stole thousands of files related to gas turbine technology to launch a rival company. This incident showcases a clear-cut case of intellectual property threat that ultimately led to an FBI investigation and conviction of the insider. 

Desjardins

In 2019, Desjardins, a Canadian financial firm, disclosed a data breach that affected nearly 3 million customers’ personal information. This scenario involved a malicious employee who copied large amounts of customer data onto a shared company drive. As a result, Desjardins experienced significant financial losses, by way of fines and costs related to customer remediation.

Detect, Investigate, and Prevent Insider Threats with Teramind

A proactive approach is essential to managing insider risk, but traditional tools lack the necessary visibility. Teramind provides a dedicated insider threat management solution that gives you the context-rich data needed to move from a defensive security posture to a commanding one.

Here’s how Teramind provides a comprehensive defense:

Gain Complete Visibility into All User Activity

You can’t protect against what you can’t see. Teramind captures all user activity on company endpoints, whether employees are in-office or remote. Monitor application and website usage, file access and transfers, emails, instant messaging, and more to get a complete, contextualized view of how your company’s data is being handled every day.

Detect Threats in Real-Time with User Behavioral Analytics

Teramind’s User and Entity Behavior Analytics (UEBA) engine automatically learns the baseline of normal behavior for each user and department. It then detects unusual behavior and high-risk deviations in real-time—such as an employee suddenly accessing sensitive files outside of work hours, searching for methods to hide their activity, or using unauthorized software. This intelligent alerting allows you to spot malicious, negligent, and compromised insider threats before they escalate into a major breach.

Prevent Data Loss with Granular Policy Enforcement (DLP)

Detection is critical, but prevention is the ultimate goal. Teramind’s robust Data Loss Prevention (DLP) features allow you to create and enforce granular rules to stop data exfiltration in its tracks. You can automatically block sensitive data from being copied to USB drives, uploaded to personal cloud accounts, sent via personal webmail, or even printed, ensuring your most valuable information stays within your control.

Accelerate Incident Response with Irrefutable Forensic Evidence

When an incident occurs, a swift and accurate investigation is paramount. Teramind provides immutable screen recordings and detailed audit trails that serve as concrete forensic evidence. This allows your security team to quickly understand the scope of a breach, identify the responsible parties, and provide clear proof for HR, legal action, or regulatory reporting.

Don’t wait for an incident to reveal your security gaps. Take control of your insider risk with a security solution built to provide clarity and enforcement.

Book a demo today or start a free trial now to see Teramind’s powerful insider threat management platform in action.

Insider Threat FAQs

What is the first step to creating an insider threat program?

The first and most critical step is to conduct a risk assessment. This involves identifying your organization’s most valuable assets (often called “crown jewels”), determining exactly who has access to them, and understanding the potential impact if that data were compromised. This foundational analysis will inform all subsequent policy, training, and technology decisions.

How should the response to a negligent insider differ from a malicious one?

The response should always match the intent. A malicious threat requires a swift security and legal response focused on containment, investigation, and mitigating damage, often leading to termination and legal action. A negligent incident, however, should be treated as a learning opportunity. The focus should be on providing targeted retraining, clarifying security policies, or improving technical controls to make it harder for the same mistake to happen again.

Why can’t my existing firewall or antivirus software stop insider threats?

Traditional security tools like firewalls and antivirus are designed to protect the perimeter—their primary job is to block known external threats from getting in. They are not built to analyze the behavior of trusted users who are already inside the network. An insider uses legitimate credentials, so their risky actions (like accessing sensitive files or emailing data) don’t trigger the same alarms as a typical external cyberattack.

Has the shift to remote work increased the risk of insider threats?

Yes, significantly. The shift to remote work dissolves the traditional office perimeter, blurs the line between personal and company devices, and makes it harder for managers to spot the subtle behavioral changes that can indicate disgruntlement or stress. This lack of direct, in-person visibility makes technology-based user activity monitoring and behavioral analytics even more critical for detecting and preventing insider risks.