How to Prevent Insider Threats in Cyber Security?

Insider threats go beyond technology and cyber hygiene checks. Find out how to prevent insider threats and adopt the best strategies to deal with them.
By SentinelOne March 20, 2025

A company runs on trust. But what happens when that trust is brutally betrayed by its employees?

AI is increasingly used in workplaces. According to a HIMSS survey, healthcare organizations reported being unaware of their employees using AI to carry out insider attacks. Three percent of respondents were responsible for malicious insider activities, and many of these healthcare firms didn’t have the necessary monitoring technologies to detect AI-based insider threats.

We can also examine history and peer into the 17th-century English Civil War. Oliver Cromwell’s soldiers invaded Corfe Castle, turning their coats inside out to reveal the Royal Army’s true colors. This act of extreme deception demonstrates how modern insider threats can operate.

An insider attack can turn your company upside down. Someone who once had access to your data, systems, and networks can sabotage your operations or cause massive business disruptions. On January 29th, 2025, the British Museum fell victim to an insider attack. The attack was caused by a grudge held by an ex-IT contractor who had been fired a week before. IBM’s 2024 Cost of a Data Breach Report revealed that 7% of data breaches were due to malicious insiders. Although insider threats are often assumed to originate from disgruntled employees, that may not always be the case.

Let’s examine this subject thoroughly and see how it all plays out. We will also discuss how to prevent insider threats.

What are Insider Threats in Cyber Security?

Insider threats in cybersecurity happen when someone inside the organization infiltrates or launches a malicious attempt.

It can be an individual who deliberately tries to abuse their access, steal data, sabotage systems, or help competitors. Or it could be due to a disgruntled employee who wants to enact revenge for personal or professional reasons.

Turncoats are very common in business settings, and a classic example is IT administrators selling private company secrets to competitors. However, not all insider threats in cybersecurity are intentional. Careless employees who unknowingly put your sensitive assets or business at risk may exercise poor security habits or lack cyber hygiene.

A staff member unaware of social engineering may accidentally click on a phishing email or link provided by hackers. They might also set up weak passwords that are too easy to guess, which could result in hacking their accounts. If someone’s credentials have been compromised, the hacker can escalate their authorization privileges and pose severe security risks. Unbeknownst to everyone, they might even lurk in the corner to perform reconnaissance and launch attacks later.

If an employee is working with cybercriminals, they might plant ransomware or malware to penetrate the organization as a spy. Staff members may also share business documents without the company’s approval and sometimes bypass IT policies for personal gain. These actions may introduce serious vulnerabilities, eventually converting into insider attacks. The gist is that insider attacks can’t occur from outside an organization. They always happen from within.

Common Causes of Insider Threats

Insider threats are entirely normal, and that’s what makes them so scary. You would never see them coming or expect the person you trust the most to do that to your organization. Insiders can launch attacks on a company for several reasons. They might be unhappy with the company’s practices or business. Authorized employees may exploit their reputation or data access to engage in illegal or unethical activities.

Since most of us people own a remote work model, it provides today’s employees much broader access to companies’ sensitive information. They can work from anywhere with the most productivity, but that also means they can launch insider threats on broader scales, much more challenging to pinpoint internal attacks because they blend in with everyday activities. Careless actions by negligent employees often go unnoticed, especially when everyone on the team is busy.

This can manifest in different ways, such as not promptly securing devices, ignoring and not strictly following the company’s security policies, and neglecting to apply updates and patches. Employees may also fail to take personal accountability for uploading or sharing their data online and underestimate essential risks.

It’s essential to clarify their responsibility and mission in protecting the company’s intellectual property.

How to Identify Insider Threats?

You can gauge insider threats by measuring employees’ motives. When they voice sentiments, pay attention and don’t just brush these details. Those little things they say and are concerned about can quickly escalate into critical issues in the future.

If your team members have weak bonds with each other, that’s a red flag. The team will have a negative attitude toward the organization until they attack it, and it’s only a matter of time, so keep that in mind.

Here are some common indicators and ways you can identify insider threats:

  • Unusual login behavior— Are your employees logging in and out erratically? Track their login patterns, and you’ll see unusual behaviors. If login attempts occur during odd hours, like outside work timings, that’s something to worry about. Al, so check the login locations from the same account. Reviewing your authentication logs and looking for unexplained failed “admin” or “test” user attempts can leave clues.
  • Excessive downloads—What’s your organization’s usual downloading quota or bandwidth? Your employees also get their fair share. If they exceed download limits for your on-premises infrastructure, you’ll know. Sudden peaks in data downloads or any downloads made from outside the network are warning signs.
  • Poor workplace performance: If an upstanding employee suddenly starts performing poorly or misbehaving with others, you know something is up. Disagreements with workplace policies or superiors or being absent too often are also indicators. If an employee unexpectedly resigns, be careful.
  • Unauthorized application usage—If there are unauthorized access attempts or application usage beyond an employee’s authority level, it’s an insider threat. Organizations daily deal with mission-critical systems like CRMs, ERPs, and financial management software. It won’t be good if an employee escalates their privileges and tampers with them. This goes for applications, user accounts, and total control over networks.

Best Practices to Prevent Insider Threats

There is no single way to guarantee insider threats prevention. You must combine multiple approaches and refine your tactics over time. Security is an iterative process that must be proactive.

So, the first thing you should do is conduct an extensive audit of your existing infrastructure:

  • Map out your inventory, assets, and resources.
  • Identify dormant and inactive accounts across networks.
  • Analyze cloud services—see which ones are in use and which aren’t.
  • Evaluate subscription models—are you overpaying for services or using a pay-on-the-go model?
  • Check resource utilization—identify anything that is being overused or underutilized.

These will serve as your starting points and give you direction on preventing insider threats.

The second thing you can do is conduct regular penetration tests and scope for vulnerabilities:

  • Look for gaps and weaknesses in your systems, as insiders can exploit these later.
  • Seal any security gaps in your apps, services, and infrastructure before they become a liability.

Now, let’s move on to the behavioral side of human interactions:

  • Observe how employees behave and work with each other.
  • Assess workplace culture—are employees on the same page, or do they often have disagreements?
  • Look for signs of dissatisfaction and examine if there are negative sentiments in the workplace.
  • Encourage open communication—if employees are afraid to voice concerns, provide anonymous reporting channels.
  • Ensure accountability for everyone handling and sharing sensitive data.

Other ways you can master how to prevent insider threats include employing security monitoring technologies:

  • Use AI threat detection tools to track baseline behaviors across resources and networks.
  • Detect behavioral deviations—these tools will alert you when something unusual happens.
  • Minimize false positives and wrong alerts to avoid misleading notifications.

Additionally, incorporate cybersecurity awareness and training programs:

  • Educate employees on cyber hygiene and ensure they follow best security practices.
  • Keep them informed about emerging threats so they know what to look for.
  • Prevent accidental leaks—employees unaware of risks may expose sensitive data unintentionally.

These are some of the best practices for preventing insider threats. But again, to gain the most insights into this issue, you must be vigilant, collect feedback, and periodically review your approach.

Legal and Compliance Considerations for Insider Threat Prevention

Regarding legal and compliance considerations for dealing with insider threats, you must be aware of various aspects.

Data protection regulations are something you should be wary of. You don’t want to violate any policies legally, so you want to stay updated with the latest industry standards. Check if your infrastructure complies with the latest frameworks, such as SOC 2, ISO 27001, NIST, CIS Benchmark, etc.

Another concern is how you process and store your customer data. If you break any relevant laws, your organization could be sued, compromising your business reputation. That is why you must ensure proper data handling practices.

Hiring internal and external auditors can help you check your security policies, workflows, and tools. They can help you.

Your organization could be troubled if data is mixed with corporate or sensitive information and shared online. You also want to implement the best access controls to limit employee access to sensitive information. Defined, strict job roles prevent unauthorized access and eliminate the potential for data leaks in the future.

You also want to establish clear incident response protocols for investigating incidents, documenting evidence, and having processes in place for notifying relevant authorities. Take disciplinary actions where needed. Readjust your protocols based on the threat landscape.

Depending on your company’s location, you must obey the jurisdiction there, set up reporting requirements to eliminate the chances of insider activity, and report these findings to regulatory bodies. You must also sign clear contracts that outline security responsibilities and potential consequences for breaking them.

You also want to categorize your data correctly based on different sensitivity levels and protect critical information. Consult legal professionals to investigate your risk profile for insider threats and ensure compliance. Getting an outside perspective can help you identify anomalies and detect future incidents.

You should also employ the best user access monitoring tools to identify outliers or signs of suspicious behavior at work.

Real-World Insider Threat Incidents

We’ve seen several cases of insider threats happening in the real world. For example, hackers frequently target healthcare organizations and steal patient records, only to sell them later on the dark web.

Privilege misuse is common; some errors stem from misconfiguration and data losses. Verizon has noted more than 83% of healthcare breaches. Compromised credentials are another reason that fuels these insider attacks.

We see common patterns every year, and one of the most recent news stories concerns Moveit, which was impacted by ransomware and denial-of-service attacks. Thanks to insider leaks, Moveit was hacked.

Within three days of deployment, MixMode uncovered several nation-state attacks and insider threats on its critical infrastructure. However, the attacks were not enough to stop the threats.

There’s also the case of North Korean hackers creating a fake IT worker persona to target the cybersecurity firm KnowBe4. The threat of this attack is that the Pentagon might use it to take control of space.

Recently, Donald Trump’s pick for the Pentagon, Peter Hegseth, has been dubbed an insider threat due to a questionable tattoo on his bicep. The tattoo, which was white supremacist, raised concerns, and a fellow service member labeled him an insider threat. There is a lot of benefit of the doubt here, and he hasn’t acted maliciously yet—but who knows?

We don’t want to get into politics in this post, but insider threats can happen anytime. Noting someone’s beliefs and sentiments is part of the process, especially when they move into more leadership roles.

Mitigate Insider Threats with SentinelOne

SentinelOne uses AI threat detection and analysis to help you detect insider threats. Thanks to its automated remediation, it can resolve all critical vulnerabilities in your infrastructure with just one click. SentinelOne can also perform cloud-based and IT auditing to ensure your infrastructure is compliant. It will check and compare your security benchmarks with the latest regulatory standards, such as PCI-DSS, HIPAA, CIS Benchmark, ISO 27001, and any upcoming frameworks.

SentinelOne’s Purple AI, a generative AI cybersecurity analyst, can provide clarity and security insights into your current standing. SentinelOne’s patented Storylines™ technology can reconstruct artifacts, conduct cyber forensics, and provide details about historical events. If you don’t have an incident response plan, SentinelOne’s Vigilance MDR+DFIR can help you.

What’s unique about SentinelOne is that it offers the best insider threat detection tools and workflows while considering the human element. SentinelOne’s team of experts is constantly available to answer all your queries; you can contact them anytime.

With its advanced endpoint protection technology, SentinelOne can monitor your endpoint activities and users. Its Singularity™ XDR Platform can scan for the latest threats and detect anomalies across your networks, users, and devices. You can expand your scope of coverage with SentinelOne’s agentless CNAPP. The CNAPP platform offers features such as cloud security posture management (CSPM), Kubernetes security posture management (KSPM), cloud detection and response (CDR), infrastructure-as-code (IaC) scanning, secret scanning, external attack surface management (EASM), vulnerability management, and SaaS security posture management (SSPM). It’s Offensive Security Engine™ with Verified Exploit Paths™ can detect and prevent attacks before they happen.

SentinelOne’s AI-SIEM solution can collect cloud telemetry data for further analysis. It can correlate events, contextualize them, and eliminate false data by cleaning it up. SentinelOne’s global threat intelligence, combined with Singularity™ Data Lake, ensures that data is collected from diverse sources. It can identify data types and provide accurate security insights from raw, unstructured information.

SentinelOne can also generate compliance reports from its unified dashboard and centralize security insights.

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Conclusion

Insider threats are real and can infiltrate even the most robust security systems. They are real-world phenomena spurred by vengeance, greed, or plain neglect. Organizations can keep these threats at bay with the right tools, such as AI-driven monitoring solutions, open policies, and a culture of trust.

All of them, from frontline employees to executive leaders, must play their part in ensuring a share of responsibility in maintaining the organization’s health. No single step can replace continued vigilance, communication, and action. Insider threats can be kept at bay, but there must be a steadfast belief in technology and the human element. So, stay ahead of the curve. Reach out to SentinelOne today for assistance.

FAQs

Why Are Insider Threats a Serious Security Risk?

Insider threats are incredibly daunting because they occur within an organization and usually have valid access to sensitive information and systems. Malicious insiders act out of personal motivations, revenge, or ideology, while unintentional insiders are unaware.

Either way, the security breaches they cause can halt operations and irreparably harm an organization’s reputation.

What are the Types of Insider Threats?

There are three broad categories of insider threats: malicious insiders who intend to misuse their privilege, negligent insiders who accidentally cause harm through negligence, and compromised insiders whose credentials are taken over by external attackers.

Each has its threat scenarios, from active sabotage or espionage to inadvertent data exposure, and each has several prevention strategies.

Why are insider threats challenging to detect?

Insider threats cannot be distinguished from typical activity, as the attackers possess valid credentials and are familiar with system architecture. Because insiders begin with valid access, their activity is more challenging to identify than external attackers, who must navigate firewalls.

Negligent errors can look like typical work procedures. This unnoticeable line will delay detection, giving malicious actors ample time to inflict damage.

What role does employee training play in preventing insider threats?

Employee training is a robust insider threat mitigation strategy that creates a security-first culture. Regular cyber hygiene, phishing, and data handling training minimizes risks from careless insiders.

Trained staff are also better positioned to recognize suspicious activity or behavior among fellow employees, allowing potential threats to be reported and addressed promptly.

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