In recent years, insider threats have become increasingly common, with the number of incidents rising by 47% from 2018 to 2020. These threats are caused by people who have access to an organization’s data or systems, and can result in significant harm to the organization’s data, reputation, and finances. In this blog post, I will explore insider threat detection and prevention, including the types of insider threats, ways to detect and prevent them, and examples of insider threats in different industries.

What are insider threats?

Insider threats are security risks that originate from within an organization. They can be caused by employees, contractors, vendors, or anyone else with access to the organization’s data or systems. Insider threats can be accidental, such as an employee unintentionally sharing confidential information, or intentional, such as an employee stealing data for personal gain or out of revenge.

Is insider threat a vulnerability?

Insider threat is considered a vulnerability because it is an internal weakness that can be exploited by an attacker. According to a recent study, insider threats account for approximately 34% of all data breaches. While this may seem like a relatively small number compared to external threats, the impact of insider threats can be significant. Insider threats can go undetected for months or even years, allowing the attacker to continue to cause harm to the organization’s data and systems.

Most common insider threat

The most common insider threat is accidental insider threat. This occurs when an employee unintentionally causes harm to the organization’s data or systems. For example, an employee might accidentally click on a phishing email, leading to a malware infection on the organization’s network.

Difference between insider and outsider threats

Insider threats are security risks that originate from within an organization, while outsider threats are risks that come from outside the organization. Outsider threats can be caused by hackers, cybercriminals, or anyone else who is not authorized to access the organization’s data or systems.

Types of insider threats

There are four types of insider threats:

Malicious insider

This is an employee who intentionally causes harm to the organization’s data or systems.

Accidental insider

This pertains to an employee whose login credentials have been breached by an external party.

Compromised insider

This refers to an employee whose login information has been accessed by an unauthorized person.

Careless insider

This is an employee who is careless with the organization’s data or systems, such as leaving their computer unlocked or sharing their password with others.

What are the three phases of insider threat?

There are three phases of insider threat:


This is the phase where the insider begins to gather information about the organization’s data and systems. They may use social engineering techniques or other methods to gain access to sensitive information.


Insiders may steal data, damage systems, or engage in other malicious activities.


The insider attempts to remove the stolen data from the organization’s systems. They may use encrypted channels or other methods to avoid detection.

Example of an insider threat

One example of an insider threat is the 2017 Equifax data breach. In this case, a software engineer who worked for Equifax allegedly exploited a vulnerability in the company’s website to steal the personal data of millions of customers. The engineer was able to access the data because he had legitimate access to the system as part of his job. This is an example of a malicious insider threat.

What are the top 5 indicators of an insider threat actor?

The top 5 indicators of an insider threat actor are:

Changes in behavior

The insider may become more secretive or defensive, or may start to exhibit unusual behavior.

Access patterns

The insider may start accessing data or systems outside of their normal working hours, or may access data that they don’t need for their job.

Data exfiltration

The insider may start copying or downloading large amounts of data, or may start using encrypted channels to transmit data.

Unauthorized access

The insider may start accessing systems or data that they don’t have permission to access, or may use someone else’s credentials to gain access.

Financial troubles

The insider may be experiencing financial difficulties that could motivate them to engage in insider threats, such as stealing data for financial gain.

Impact of Insider attacks

• Unauthorized removal, copying, transfer or other methods of exfiltration of data without prior approval.
• Inappropriate use of organizational resources for activities that are unauthorized or not related to the business.
• Unauthorized modification of data by tampering with it.
• Intentional deletion or destruction of valuable and sensitive organizational assets.
• Downloading information from questionable sources without proper verification.
• Usage of pirated software that may contain malicious code or malware.
• Network eavesdropping and intercepting packet data without consent.
• Spoofing and impersonating other individuals or entities through illegal means.
• Planning and executing social engineering attacks to deceive individuals and gain unauthorized access.
• Intentional installation of malicious software, such as viruses or malware, to harm the organization or steal sensitive data.

insider threat

Insider threat detection

Insider threat detection involves monitoring an organization’s data and systems for suspicious activity. This can be done using a variety of techniques, including:

User behavior analytics

This involves monitoring user activity to detect abnormal behavior, such as accessing data outside of normal working hours or downloading large amounts of data.

Data loss prevention

This involves monitoring data leaving the organization’s systems to detect unauthorized data exfiltration.

Endpoint detection and response

This involves monitoring endpoints, such as laptops and mobile devices, for suspicious activity.

Network monitoring

This involves monitoring the organization’s network for suspicious activity, such as unusual data flows or attempts to access unauthorized systems.

Ways to prevent insider threats

Access Control

Limiting access to sensitive data and systems can be achieved through role-based access control, attribute-based access control, and mandatory access control. Organizations can implement these access control mechanisms to restrict access to sensitive information, thereby reducing the risk of insider threats.

Security Awareness Training

Training employees on how to identify and report suspicious activities can increase their vigilance and help prevent insider threats. Organizations can conduct security awareness training to educate employees about the latest cybersecurity threats, such as phishing, social engineering, and ransomware attacks, and how to identify and report these threats.

Background Checks

Conducting thorough background checks on new hires can help identify potential insider threats before they are hired. Organizations can use pre-employment screening tools, such as criminal background checks, employment history checks, and education verification, to identify red flags and ensure that only trustworthy individuals are hired.

Two-Factor Authentication

Implementing two-factor authentication can make it more difficult for insiders to gain unauthorized access to systems and data. Organizations can require employees to provide two forms of identification to access critical systems and data, such as a password and a token or smart card, thereby reducing the risk of insider threats.

Monitoring and Auditing

Regularly monitoring and auditing user activity can help detect and prevent insider threats. Organizations can review access logs, monitor data exfiltration, and conduct manual and automated audits to detect anomalies and identify potential threats.

Incident Response Plan

Having an incident response plan in place can help organizations respond quickly and effectively to insider threats. The plan should include procedures for investigating and containing insider threats, as well as notifying affected parties, and should be regularly tested and updated to ensure its effectiveness.

Implementing a Comprehensive Security Policy

Creating a comprehensive security policy that outlines the organization’s expectations and guidelines for employees and contractors can help reduce the risk of insider threats. The policy should include provisions for access control, data protection, and incident response, among other things.

Implementing a Threat Detection Program

A threat detection program can proactively identify and prevent insider threats by detecting, investigating, and mitigating threats. Organizations can use a combination of technical controls, such as intrusion detection systems, and human intelligence, such as employee reporting, to create an effective threat detection program.

Securing Physical Infrastructure and Screening New Hires

Organizations can protect against unauthorized access to sensitive areas by securing physical infrastructure, such as server rooms and data centers, and minimize insider threats by conducting thorough background checks for new hires.

Using Multifactor Authentication and Secure Devices

Requiring multifactor authentication and securing devices with encryption, antivirus software, and regular updates can enhance security.

Segmenting LANs and Identifying Areas of Risk

Limiting access to sensitive information and resources by segmenting LANs and identifying areas of risk.

Using Threat Modeling and Implementing Perimeter Tools

Identifying potential attack scenarios and planning mitigation strategies by using threat modeling and implementing perimeter tools, such as firewalls and intrusion detection systems, can help prevent unauthorized access and reduce the risk of insider threats.

Sealing Information Leaks and Investigating Unusual Activities

Monitoring data flows and implementing data loss prevention solutions to seal information leaks, and investigating unusual activities to identify potential threats.

Identifying Compromised Accounts and Conducting Sentiment Analysis

Identifying compromised accounts and locking them down to prevent further damage, and conducting sentiment analysis to detect negative sentiment and identify potential threats.

Monitoring Third-Party Access and Conducting Regular Audits

Monitoring third-party access to prevent unauthorized access to sensitive data and resources, and conducting regular manual and automated audits to detect anomalies and identify potential threats.


Insider threats are a serious concern for organizations of all sizes and industries. While it may be tempting to focus solely on external threats, it is important to remember that insiders can cause just as much damage. By implementing technical controls, conducting security awareness training, and monitoring user activity, organizations can help prevent insider threats and minimize the impact of any incidents that do occur.

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