What is an insider threat?
An insider threat is an employee (current or former), contractor, or other individual that has access to an organization's proprietary information and exploits that knowledge for personal or monetary gain.
These threats represent a significant cybersecurity risk, as anyone with authorized access—such as employees, partners, vendors, or suppliers—can misuse their permissions to compromise sensitive data or systems.
Not all insider threats are necessarily malicious. Some occur due to human error and some occur because an employee is just trying to work more efficiently with tech or apps they prefer.
In today’s relentless cyber threat landscape, it’s easy for companies to spend an excessive amount of time, money, and effort to protect themselves from external attacks. But with the shift to remote and hybrid work environments, the worst threats might be sitting right in front of you–operating from the inside–risking the exposure of trade secrets, HR information, customer data, and more.
Because so many individuals have legitimate access to company systems, it’s easy for malicious or even unintentional leaks to happen under your company’s radar.
In this guide, you will discover how to identify insider threats, how they occur, and tips for defending your organization against them.
Insider threat types and examples
Common types of insider threats
1. Negligent users - Employees who unintentionally commit data breaches by leaving sensitive data unsecured. This type of breach can occur if an employee leaves a work device unlocked or in an area where it can be stolen. Negligence can also come in the form of employees who bypass security protocols they feel are unnecessary or bothersome.
2. Departing or disgruntled employees - Employees that voluntarily or involuntarily depart a company and exploit company data for personal or monetary gain. An example of this would be a disgruntled employee that sells confidential and proprietary information about their organization to a competitor.
3. Espionage - Inside agents that operate on behalf of an external group to carry out a data breach or other attack. These threats can be as innocent as an employee that is duped by social engineering or as insidious as being blackmailed or bribed to divulge information.
4. Third-party threats - Outside parties with access to an organization's networks and information. These insider threats can occur in the form of a contractor using company access credentials to obtain and share sensitive information or intellectual property for several reasons.
Real examples of insider threat
Insider threats might seem alarming in theory, but they’re even more dangerous in real-life. Here are a few examples of insider threats:
- In 2022, Yahoo sued a former research scientist who stole proprietary source code about their AdLearn product. Minutes after receiving a job offer from a competitor, the employee downloaded approximately 570,000 pages of Yahoo’s intellectual property (IP) to his personal devices, knowing that the information could benefit him in his new job. In the lawsuit, Yahoo claimed the stolen data would give competitors an immense advantage.
- In 2020, Stradis Healthcare let go of employee Christopher Dobbins who then, acting in revenge, penetrated the company’s network. Once he was in, he gave himself admin access and edited or deleted over 120,000 records, delaying PPE shipments for months.
- In 2020, former Google executive Anthony Scott Levandowski stole trade secrets from the company’s self-driving car department and took them to his new job at Uber. Levandowski admitted that Google may have lost up to $1,500,000 due to his theft.
These are just three examples of real insider threats that happen every year, causing severe financial and reputational damage.
Technical indicators of insider threats
With so many ways for insider threats to arise, the best way to detect and ultimately deflect them is to look for consistent data movement and digital signals.
Insider threat actors can leave a trail of activities or characteristics that suggest corporate data is at a higher risk of exposure or exfiltration. While each of the below indicators may be benign on its own, a combination of them can increase the priority of data loss events—making it clearer that there’s an insider threat occurring:
- Zip file exfiltration
- Attachment sent via ProtonMail
- Corporate data movement to personal versions of approved applications
- Accessing information that isn’t relevant to their job function
- Spikes in outbound data exfiltration attempts
- Airdrop transfers
- Renaming files where the file extension doesn’t match the content
- Installing hardware, software, or malware
Keeping an eye on these signals can help security teams spot unusual activity and stop insider threats before they turn into a breach.
Some cyber security vendors might suggest monitoring employee behavior—particularly for actions showing that they’re disgruntled or dissatisfied—to detect an insider threat, but this is often unproductive.
How to detect insider threat attacks
A company can use both human and technological insight to detect insider threats. As an organization’s personnel typically have direct contact with their peers, they’re likely to be the first to detect suspicious behavior. To enhance insider threat detection, organizations can also employ software solutions that monitor user activity, access management, and behavior analytics.
The challenge of stopping insider threat
While organizations have long been focused on stopping hackers outside the organization from breaching security defenses, most have little protection against an insider threat.
There are at least three types of insider threat profiles. With a Malicious Insider Threat, an employee inside the organization purposely seeks to steal data, leak information or otherwise damage the organization. A Careless Insider Threat occurs when employees don't understand security policies or follow security rules, putting the organization at risk for malware infections and data leaks. And the Compromised Insider Threat involves an employee whose email account has been taken over by hacker through credential harvesting, social engineering, phishing emails or malware in order to steal information or make fraudulent financial transactions.
Almost every insider threat involves email. Email messages are frequently the source of attacks – messages that contain malicious email attachments and URLs are a common technique for launching advanced persistent threats and other attacks. And email is often involved in data leaks, whether malicious or inadvertent. To defend against an insider threat, organizations need insider threat detection for internal email that can quickly identify and remediate an attack or data leak. That's where Mimecast can help.
How to protect against insider threats
While upper management and security teams can certainly watch out for digital and behavioral indicators, that shouldn’t be a company’s only protection method. Instead, they should approach their insider threat program from three perspectives: establishing normal user behavior, identifying and protecting critical assets, and mitigating risk.
Additionally, providing continual training to employees will keep security top of mind and create a culture around security.
Create a baseline of trusted activity
You need to know what trusted activities are before you can spot risky data access movement. Your optimal cyber security software will have built-in features that establish and infer a baseline of trusted data access activity to use as a comparison when tracking everyday data movement.
The activity of interest might be authentication methods, access times and VPN logs. Your cyber security system should alert security teams when anomalies appear so they can review and determine whether the irregularities are, in fact, potential insider threats.
Gain visibility of all your data and its movement
You may have heard of protecting your most critical assets, but it’s easier and more efficient to treat all data as essential and monitor its movement accordingly.
Inadvertent data exposure occurs up to 34 times per user every day, so protecting all data as if it’s critical helps minimize the risk of accidentally moving sensitive information and creating a situation for IP theft.
Ensure employees know that monitoring data movement to untrusted locations isn’t the same as surveillance. Instead of tracking keystrokes, taking pictures of screens, watching performance or other invasive activities, a company monitoring the data it owns is in the interest of employees and the company since it protects innovation and competitive edge.
Manage insider threat by addressing risk
The 2023 Data Exposure Report by Code42 (now part of Mimecast) found that CISOs rank insider risk as the most difficult threat to detect within their organizations. Insider risk is data exposure that jeopardizes the well-being of an organization and its employees, customers, or partners.
Instead of looking for a needle in a haystack and that one person who’s an insider threat, consider implementing a modern data protection strategy by monitoring activities that place sensitive information at risk. This approach prepares you to respond to any potential data breach, regardless of the intent behind it.
Executing data protection isn’t about surveilling employees or waiting for them to slip up. It’s about monitoring data changes and movement, looking for risk indicators and prioritizing that risk. Based on the priority, you can take action quickly to contain damage and prevent a breach.
The quickest way to discover insider risks is with the assistance of intelligent software. Unlike humans, AI-based tools can continuously monitor a company’s systems and bring risks that you may not even notice to light. The best platforms scan all systems for vulnerabilities, empowering security teams to patch them quickly.
Train employees and create a culture of security
Another component of data protection is providing continuous training to employees. Training that focuses on security best practices and the “why” behind policies can benefit a team. Reminding employees of why policies are in place can cut down on security evasion. Keeping best practices top of mind fights negligence and encourages employees to establish good behaviors that follow a company’s protocols.
By emphasizing the importance of cyber security company-wide businesses create a culture that places value on security and risk management that can ultimately lead to fewer insider threats.
Prevent an insider threat with Mimecast
Mimecast provides cloud-based services for email security, continuity and archiving, managed from a single pane of glass, that help reduce the cost and complexity of advanced threat protection.
To detect and prevent an insider threat, Mimecast offers Internal Email Protect, a threat monitoring and remediation service for internally generated email. As part of Mimecast's email security offering, this insider threat program lets you monitor, detect and mitigate email-borne security threats that originate from within your organization.
Internal Email Protect scans all email along with attachments and URLs to identify malware and malicious links. Mimecast can also detect an insider threat with content filtering to enforce data leakage prevention services.
Protect against insider threats with Mimecast Incydr
From harming a company’s reputation with customers to stripping them of funding to exposing proprietary innovations, insider threats can have devastating consequences. Part of the reason safeguarding against insider threats is challenging is because legacy DLP software has a siloed view of data movement, missing dozens of threatening exfiltrations. Instead of guessing at which exfiltration is a threat, consider a modern approach to data protection.
Mimecast Incydr is an intelligent data protection solution that identifies risky data movement–not just the exfiltrations that security has classified–helping you see and stop potential insider threats. Incydr automatically detects data leaks to untrusted cloud apps, blocks unacceptable exfiltrations, and tailors security’s response based on the offender and the offense. Employees who make security mistakes are automatically sent educational training to correct user behavior and reduce insider threat risk over time.
FAQs on insider threat
What are common indicators of insider threats?
Some common indicators of insider threats are:
1. Suspicious logins
2. Use of unauthorized applications
3. Increased data downloads
4. Erratic or unusual employee behavior
5. An administrator granting unauthorized users access to files
What are some best practices to prevent insider attacks?
To prevent insider attacks before they occur, organizations can:
1. Use access management software to give users access to information that only pertains to their role and job functions.
2. Carefully screen new hires. This includes background and drug screenings and checking references.
3. Hold yearly Security Awareness Training.
4. Monitor employee behavior and internet usage with analytics and monitoring software.
Who is most vulnerable to an insider threat attack?
Any organization of any size can fall victim to insider threat attacks. However, organizations that regularly handle highly confidential and sensitive information are more susceptible as the data they hold can be extremely valuable. Some organizations that may be at heightened risk are:
- Healthcare institutions
- Government agencies
- Financial institutions
- Software companies
