What is an Insider Threat?

Published On - March 20, 2024

An insider threat refers to malicious activity against an organization that originates from users with legitimate access to an organization’s network, applications or databases. It usually occurs when a current or former employee, or third parties with legitimate access to the organization’s sensitive information or privileged accounts, misuses their access to the detriment of the organization’s networks, systems and data.

Insider threats are the cause of most data breaches, but they are more difficult to identify and prevent than external attacks. Typically, cybersecurity solutions such as firewalls, intrusion detection systems and anti-malware software have focused on external threats, leaving the organization vulnerable to attacks from inside. If an attacker logs in using an authorized user ID, password, IP address and device, they are unlikely to trigger any security alarms, so it becomes hard to distinguish between normal and destructive behavior. Therefore, to effectively protect your digital assets, you need an insider threat detection strategy that combines multiple tools to monitor insider behavior while minimizing the number of false positives.

Learn How Lepide Helps in Insider Threat Detection and Prevention

In this article, we delve into the precise definition, diverse types, and poignant examples that highlight the significance of the pervasive insider threat. Reports suggest that 68% of companies are concerned or very concerned about insider risk as their organizations return to the office or transition to hybrid work. Now more than ever it’s important to fully understand the insider threat.

Types of Insider Threats

An insider threat may be executed intentionally or unintentionally. Here are 3 types of insider threats:

1. Careless Insider

Unintentional insider threats can be from a negligent employee who unknowingly exposes the system to outside threats. This is the most common type of insider threat, resulting from mistakes, such as leaving a device exposed or falling victim to a scam. For example, an employee who intends no harm may unintentionally click on an insecure link, infecting the system with malware.

2. Malicious insider

Malicious insider threats, also known as Turncloaks, are those who maliciously and intentionally abuse their privileged access to steal information or degrade systems for financial or personal incentives. For example, an individual who holds a grudge against a former employer, or an opportunistic employee who sells confidential information to a competitor. Malicious insiders have an advantage over other attackers because they are familiar with the security policies and procedures of an organization, as well as its vulnerabilities.

3. A Mole

A mole is an outsider but one who has gained insider access to an organization’s privileged network. They may pose as a vendor, partner, contractor, or employee, thereby obtaining the privileged authorization they otherwise would not qualify for. Their intent is to abuse this level of access to steal and sell data or use it for other malicious purposes, such as threatening to leak confidential information if an organization doesn’t comply with their demands.

Moles often exploit the existing business relationships of a company since most organizations work with various freelancers and contractors. They use stolen credentials or social engineering to gain access to this extended network and the company data that legitimate business partners work with.

No matter the intent, the result is the same – the compromised information security of an organization.

Examples of Insider Threats

Here are three examples of insider threats from recent memory:

  1. Equifax Data Breach (2017): This massive breach exposed the sensitive data of over 147 million Americans. A temporary employee with administrative access to a server containing personal information exploited a vulnerability in Apache Struts, a web application framework. The vulnerability allowed unauthorized access through a specially crafted web request. The employee used this to gain access to the server and download vast amounts of data.

    Apache Struts had a known vulnerability (CVE-2017-5638) that was exploitable through a remote code execution (RCE) attack. The insider likely used a publicly available exploit kit to target the vulnerable server and gain access. Once in, they could move laterally within the network and access sensitive data.

  2. TJX Companies Hack (2003-2005): A ring of hackers led by a disgruntled security guard at a subcontractor firm infiltrated TJX Companies’ network. The security guard used his legitimate access to install malware on the company’s systems. This malware captured credit card data as it was swiped at TJX stores for over two years.

    The insider likely used malware like a keylogger or packet sniffer. Keyloggers record keystrokes, potentially capturing credit card information. Packet sniffers capture data flowing across a network, which could include credit card details transmitted unencrypted.

  3. WikiLeaks (2010): Former U.S. Army intelligence analyst Chelsea Manning downloaded and leaked classified military and diplomatic documents to WikiLeaks. Manning had legitimate access to these documents due to her job role but bypassed security protocols to download them onto unauthorized devices.

    Manning may have used removable storage devices like USB drives to transfer the classified data. She might have also exploited trust relationships with colleagues to gain access to additional information or bypass security measures.


These are just a few examples, and insider threats can take many forms. They highlight the importance of both technical controls (like patching vulnerabilities) and a strong security culture within organizations.

Indicators of Insider Threats

Below are some of the most common indicators of insider threats:

1. Unusual Network Activity

Unusual network activity is a common indicator of an insider threat. An employee who is preparing to steal data or engage in other malicious activities may access resources that he or she has never used before or access files that are out of his or her usual working hours. Monitoring network activity can help organizations detect such behavior.

2. Accessing Unauthorized Information

Insiders with malicious intent may try to access information that they are not authorized to view or download. This could be sensitive/confidential data or proprietary information, such as intellectual property. Organizations must monitor such activities closely, and if detected, take swift action to prevent data theft.

3. Changes in Work Habits

A change in work habits can be a sign of an insider threat. An employee who is typically punctual, but suddenly starts arriving late or leaving early might be planning a data breach. Similarly, an employee who suddenly stops showing up for meetings or ceases collaborating with co-workers and supervisors could be a cause for concern.

4. High Level of Access Privileges

Another red flag is individuals who have high-level access privileges within the organization. Not only does this increase the chances of data theft, but it also increases the severity of the risk. Organizations should monitor and limit access privileges to reduce the likelihood of insider wrongdoing.

5. Active Job Search

An insider who is actively seeking new employment may be planning to steal organizational data or intellectual property before departing. Without causing any privacy violations, organizations should keep an eye out for employees actively seeking employment elsewhere.

6. Recent Security Violations

Employees who have recently been disciplined for security violations are also much more likely to commit malicious activities or attempt to steal information. Organizations must monitor these employees to mitigate the potential risk of future security violations.

7. Financial Difficulties

Insiders who are experiencing financial difficulties are more likely to steal data to sell to third parties or commit fraudulent activities. Organizations should look out for behavior that may indicate that an employee is experiencing financial difficulties, without violating their privacy.

8. Use of Unauthorized Software

When employees download and use software without proper authorization, they are breaking company policies and potentially compromising the security of the organization. This could include malware or other malicious software that could infect the company’s network, or software that is not secure and could allow for unauthorized access to sensitive information.

How to Detect and Prevent Insider Threats

Insider threats pose a serious risk to organizations. To combat them, we need a two-pronged approach: prevention and detection.

On the preventative side, fostering a strong security culture is essential. Employees aware of data security policies and how to report suspicious activity become the first line of defense. Additionally, granting access based on job roles (least privilege) and implementing data loss prevention (DLP) solutions can minimize potential damage. Endpoint security software and multi-factor authentication (MFA) further tighten security by detecting malware and making unauthorized access harder.

Insider threat detection involves monitoring user activity for deviations from normal patterns through User Behavior Analytics (UBA). Security Information and Event Management (SIEM) systems aggregate data from various security tools, providing a centralized view for faster identification of suspicious activity. Regular log monitoring for failed logins, unusual data access, or privilege escalations can also be helpful. Finally, having a well-defined incident response plan ensures a coordinated and efficient response to potential insider threats.

By combining these preventative measures and detection tactics, organizations can significantly reduce the risk of insider threats and protect their valuable data. Remember, a layered approach is essential for effective protection.

How to Report Insider Threats to Authorities

Reporting an insider threat is a crucial step in maintaining the security of an organization. If you suspect or have evidence of insider threat activity, follow these general steps:

1. Follow Company Policy

Check your organization’s policies and procedures regarding reporting insider threats. Many companies have specific guidelines for reporting security incidents.

2. Contact IT or Security Department

Reach out to your organization’s IT or security department immediately. They are typically responsible for handling security incidents.

Provide Detailed Information

· When reporting, be prepared to provide as much detailed information as possible, including the nature of the threat, individuals involved, specific incidents, and any evidence you may have.

4. Use Anonymous Reporting Channels

Some organizations have anonymous reporting channels to encourage employees to come forward without fear of reprisal. Check if such channels exist and use them if necessary.

5. Document Evidence

If you have any evidence such as emails, documents, or other digital artifacts, make sure to document and preserve them. Do not tamper with any evidence.

6. Maintain Confidentiality

Be discreet about the information you possess to avoid compromising ongoing investigations. Share details only with authorized personnel.

7. Cooperate with Investigations

If an investigation is initiated, cooperate fully with the designated security or legal personnel. Your input may be crucial to resolving the issue.

8. Report to Higher Authorities if Necessary

If you feel that the internal reporting process is not effective or if the threat involves high-level personnel, you may need to report to higher authorities, such as senior management or legal departments.

9. Escalate to Law Enforcement if Required

In extreme cases, where there is a serious threat or criminal activity, it may be necessary to involve law enforcement. Coordinate with your organization’s legal team before taking this step. Remember, insider threat situations can be complex, and it’s important to follow the appropriate procedures to ensure a thorough and lawful investigation. Always prioritize the safety and security of your organization.