Insider threats 101: Detect, investigate, and then mitigate

Suparna Barman

Apr 206 min read

What is an insider threat?

Any insider, be it an employee, former employee, contractor, third-party vendor, or business partner, who uses their authorized access or sensitive knowledge of an organization to cause harm to that organization is considered an insider threat.

A threat actor, just like any other employee, has genuine credentials and access to the organization's systems and data, making it difficult to distinguish between normal and malicious activity. As a result, insider attacks are considered one of the most dangerous threats, and it can be a major pain for even the best security teams to detect them. Did you know that 98% of organizations feel vulnerable to insider attacks, as per the 2021 Insider Threat Report by Cybersecurity Insiders.

Unlike an external attacker, insiders know about all the nuts and bolts of an organization, making an insider data breach even more costly for businesses.

Types of insider threats

Insider threats are primarily of two kinds: unintentional and intentional.

Unintentional threat

Those who unintentionally become a part of the breach: negligent or accidental behaviors are the main reasons for most unintentional insider breaches.

  • Negligence: Carelessness of insiders can put an organization at risk. This type of insider is generally aware of security and IT policies but chooses to neglect them, putting the firm in danger.
  • Accidental: Employees who are unknowingly duped into engaging in malicious behavior fall into this category. An insider of this type inadvertently exposes an organization to an unwanted risk via phishing, social engineering, and so on.

Intentional threat

Intentional threats, on the other hand, involve employees who take part in malicious activities on purpose with a motive of personal benefit or to harm the organization. This type of insider is also referred to as a malicious insider. Dissatisfaction over a perceived grievance, ambition, or financial constraints are some of their driving factors.

Other threats

  • Collusive threat: When one or more insiders collaborate with outsiders, like a company's competitors to sabotage an organization. For financial or personal gain, they take advantage of their access to steal the sensitive data and disrupt business operations.
  • Third-party threat: Threat posed by an insider who is not a formal member of the organization, such as contractors and vendors.

Threat detection and remediation

Threat detection is the process through which organizations identify the potential malicious insider, usually because of their suspicious behavior or activities. Detecting a threat as early as possible can help an organization control the damage to a great extend.

Malicious insiders typically leave suspicious patterns, such as:

  • Illegally pulling out client data and storing it on personal drive.
  • Misusing privilege access by stealing the company's sensitive data.
  • Escalating privileged access to gain access to other classified data.
  • Logging in from suspicious geolocations or devices.

Tracking these trails can eventually lead to identifying the insider threat. A centralized monitoring solution, such as a security information and event management (SIEM) platform, along with a user and entity behavior analytics (UEBA) solution can easily track digital trails of employees.

Once this information has been centralized, a baseline of usual behavior for every user and machine can be established. A deviation from this state is considered abnormal behavior and is further assessed for risks. An increase in unusual behavior can lead to a high risk score. If a user's risk score surpasses a particular threshold, the system flags a security alert. To prevent false alerts, take a user-focused approach by tracking deviations for individual users and comparing them to others in the same location with the same job designation.

To remediate insider threats at the earliest stage of an attack, an organization must establish an efficient incident response and recovery security strategy. This would be a manual for managing the aftermath of any security failure or breach. Organizations must have strong recovery programs in place in order to limit the damage caused by events and lower both recovery times and costs.

Security orchestration, automation, and response software works by gathering security data and alerts from numerous sources. By accumulating and studying all historical data, it helps the organization automate a standardized threat detection and remediation plan to respond to low-level security events.


Due to the complexity of detecting insider threats, it's difficult for a single cybersecurity solution to identify and mitigate them. The way to deal with this modern cyberthreat is to adopt an approach consisting of a range of security solutions, including:

  • Data loss prevention technology helps organizations secure their data and prevent unwanted destruction of sensitive data during a cyberattack.
  • Multi-factor authentication adds extra layers of security to the login process and helps mitigate the risk of threat actors exploiting user credentials.
  • Privileged access management (PAM) is a cyber strategy to protect sensitive assets against security breaches. PAM is aligned with the least privilege policy, which implies that an employee should be provided with the least amount of access required to get their job done. With PAM, access of sensitive data can be carefully managed from a centralized place, which helps prevent the misuse of privilege access by a malicious insider.

It's always better to have preventative measures in place rather than trying to fix problems as they occur. A threat prevention strategy should start with building information governance, which covers all aspects related to an organization's information, starting from it's creation to its deletion.

Sound information governance offers a clear and detailed understanding of an organization's assets and processes. To detect and monitor anomalies in business activities, it should be complimented with UEBA, SIEM, and advanced forensic data analytics. But most importantly, legal considerations must be taken. Each country is governed by different privacy laws, meaning organizations must comply with their respective laws and create their own policy and regulations accordingly.

The consequences of an insider incident can devastate an organization and cause long-term negative consequences. However, a proactive threat prevention plan can help IT administrators to identify anomalous activity as early as possible and put a stop to attacks at their earliest stages.