Insider Threat Program Best Practices for Small Businesses

An insider threat program is a set of policies, training, and controls that helps an organization prevent, detect, and respond to harm caused by people who already have authorized access, whether the harm is intentional or accidental. For a defense manufacturer, that access includes CUI, customer drawings, and the shop-floor systems that make the parts. 

Most guides are written for large agencies, or by vendors selling monitoring software. This one is for the shop that has to manage insider threats with limited staff: what’s actually required, what’s worth doing anyway, and where to start on insider risks without turning the workplace into a surveillance operation. 

What Is an Insider Threat Program? 

The Cybersecurity and Infrastructure Security Agency (CISA) defines an insider as any person who has or had authorized access to, or knowledge of, an organization’s resources, including its people, facilities, information, equipment, networks, and systems. An insider threat is the potential for that person to use their access or understanding to harm the organization, whether they act intentionally or unintentionally. CISA’s insider threat mitigation guidance is explicit on that point. The harm can include intellectual property theft, unauthorized disclosure of sensitive information, sabotage, or simple damage from a mistake. 

“Insider” covers more than employees. CISA’s examples include contractors, vendors, custodians, and repair people who’ve been given a badge or access device, which on a manufacturing floor means maintenance techs and equipment vendors too. 

The goal of an insider threat program is to prevent insider incidents or catch them early, and to manage the response when something happens. That’s what insider threat prevention means in practice: stopping the accidental ones as well as the malicious ones, and mitigating the damage when prevention fails. Part of the value is deterrence too, because people behave differently when they know access to sensitive data is logged and reviewed. 

What Are the Types of Insider Threats? 

Three types come up often in insider threat frameworks: 

• Malicious insiders act with malicious intent: stealing intellectual property or CUI, committing fraud, or sabotaging systems or product. 

• Unintentional or negligent insiders create what are sometimes called unintentional threats, causing harm by mistake or by taking a shortcut: a misdirected email, a drawing copied to a personal device to meet a deadline, a shared folder opened too wide. 

• Compromised insiders are legitimate users whose credentials have been stolen, so an outsider is operating with an insider’s access. 

A program that only hunts for the villain misses two of the three. Understanding insider threats means covering mistakes and stolen credentials as well as bad intent. 

It also helps to keep the scale in perspective. Verizon’s 2026 Data Breach Investigations Report found internal actors in 12% of breaches overall, and its manufacturing snapshot shows 5%, against 95% for external actors. Insider risk is real, but external threats account for most breaches, which is a good reason to build a program sized to your business rather than copying one designed for an intelligence agency. 

Who Is Required to Have an Insider Threat Program? 

It depends on your situation, and the answer is more nuanced than most guides suggest. 

Notice the difference between a program and training. The NISPOM requires cleared contractors to establish and maintain an insider threat program, tied to Executive Order 13587 and the National Insider Threat Policy, and the senior management official must appoint an ITPSO in writing. Contractors must also keep written procedures for the program. We cover how clearances work in our guide to facility security clearance and NISPOM. 

NIST SP 800-171 is narrower. It requires security awareness training on recognizing and reporting potential indicators of insider threat, plus the personnel controls above, but it doesn’t require a formal insider threat program. In practice, assessors still look at your insider threat policy and procedures along with the training materials, so having something written down matters. For the broader picture, see our guide to DFARS compliance. 

In several recent CMMC Level 2 readiness assessments we’ve conducted, insider-threat awareness training was missing, often alongside no personnel screening and no formal offboarding process. By contrast, one client requires DCSA, CUI, and insider-threat training for everyone and stores the certificates centrally, which is exactly the kind of evidence an assessor wants to see. 

What Should an Effective Insider Threat Program Include? 

CISA describes the key steps as define, detect and identify, assess, and manage. A comprehensive insider threat program for a small shop usually includes: 

• A named owner. For cleared contractors that’s the ITPSO. Everyone else should still pick one accountable person, supported by HR and management. 

• Written insider threat policies. What’s expected of people with access, what’s monitored, and how to report a concern. 

• Personnel screening. Checks before someone gets access to CUI systems, as NIST 3.9.1 expects. 

• Insider threat awareness training. Teaching people to recognize and report potential indicators, as NIST 3.2.3 requires. We cover how this fits into a broader program in our guide to security awareness training. 

• A reporting channel people trust. Clear, simple, and safe to use. 

• Access limits. Least privilege for CUI, drawings, and controlled data, including who can reach controlled technology, which we cover in our guide to the technology control plan. 

• Detection that fits your size. Covered below. 

• Offboarding and transfer procedures. Protecting CUI systems when people leave or change roles, as NIST 3.9.2 expects. 

• A response plan. Who gets called, in what order, and what happens to access and evidence. 

• A regular review. At least annually, because threats evolve and so does your workforce. Cleared contractors must perform a formal self-inspection, including of the insider threat program, at least once a year. 

How to Implement an Insider Threat Program in a Small Shop 

Implementing an insider threat program doesn’t require a security department. These insider threat best practices work for a small shop, and the order matters when you’re establishing an insider threat program from scratch: 

• Name an owner and bring in HR. Insider issues are people issues. HR, management, and IT all have to be in the room. 
• Know what you’re protecting. List your CUI, controlled drawings, programs, and customer data, and where each one lives. 
• Limit access to what people need. That includes paper. In one recent assessment, we recommended sign-in and sign-out logs for controlled drawings, so physical documents have the same accountability as digital ones. 
• Screen and train. Run background checks before granting CUI access, and train everyone on insider threat indicators, using short training sessions rather than one long annual lecture. One manufacturer was advised to run at least one basic background check on a CUI user before its assessment. 
• Build offboarding that moves faster than the person. A termination checklist should cover electronic access, building access, keys, and locks, plus any vendor or customer accounts the person could reach. In a CMMC program we’re helping finalize, the draft policy sets four hours as the window to revoke access after notification, a clear and testable standard. 
• Add detection that fits. More on that next. 
• Practice. Run a tabletop exercise at least once a year, ideally with an insider scenario. 

Insider Threat Detection: What to Watch and How 

CISA is clear that detecting insider threats takes both human and technological elements. People notice concerning behavior, and systems notice concerning activity. Neither is enough alone, and neither is proof of a potential insider threat on its own. 

Human indicators. Common indicators of an insider threat in training programs include attempts to access information not needed for the job, repeated policy violations, unexplained interest in controlled data, and concerning behavior that managers or coworkers report. An indicator is a reason to look, not proof of anything. Treat each one as a prompt for a careful, fair review of the security risks involved, never as a verdict. 

Technical indicators. Look for unusual access to CUI repositories, bulk downloads or large copies of drawings, use of removable media, uploads to personal email or cloud storage, and access at unusual times or from unusual places. Some tools learn baselines of normal behavior for each user and flag deviations, often called user and entity behavior analytics. They can help, but they aren’t required to start. 

Think in control types. Preventive controls stop an action, such as least-privilege access and blocked removable media. Detective controls notice it, such as logs and alerts on your CUI repository. Corrective controls fix it, such as disabling an account or revoking a session. A small shop usually gets the most value from combining basic preventive controls with logging and alerts on its most sensitive data. 

Balancing Security Measures With Trust 

An insider threat program works best inside a healthy security culture, and the balance between security and trust is the hard part. If employees feel watched rather than protected, they hide mistakes, which is exactly the opposite of what you want. 

A few principles help: 

• Be transparent. Tell people what’s monitored and why, and put it in writing. 

• Apply it consistently. The same rules for executives and shop-floor staff. 

• Involve HR and counsel before you monitor. Rules about employee monitoring vary, so get legal input before turning anything on. 

• Make reporting safe. People should be able to raise a concern, or admit a mistake, without fear. 

The aim is to protect the business and the people in it, not to create suspicion. 

Insider Threat Incident Response: What to Do When You Suspect One 

If you suspect an insider incident, the sequence matters: 

1. Don’t confront the person alone. Involve HR and, where appropriate, legal counsel before any conversation. 

1. Preserve evidence. Keep logs, files, and account records intact. Cleanup that destroys evidence makes everything harder. 

1. Contain access. Disable accounts, revoke active sessions and MFA devices, and consider vendor or partner accounts the person may have touched. 

1. Find out what was accessed. Scope the incident before deciding what you have to report. 

1. Check your reporting duties. If CUI may be exposed, the 72-hour DFARS reporting clock may apply. Your cyber insurer may also need notice. 

1. Document everything. What was seen, what was done, and by whom. 

We recently ran a tabletop exercise with a manufacturer built around exactly this kind of case. The scenario started with an employee’s accidental PII disclosure, followed by misconduct and a termination. Then repeated shared-drive changes and an unfamiliar administrator account surfaced, and the account traced back to a vendor that had hired the former employee. The team worked through removing electronic and building access, recovering keys, considering new locks, excluding the former employee from vendor accounts and meetings, confirming NDA obligations, preserving evidence, contacting counsel and the insurer, and assessing customer impact. It was a scenario, not a real incident, but the questions it raised are real: who has the vendor relationship, who can disable access, and who decides. 

If you can’t say with confidence who owns insider risk at your company, how quickly you could revoke someone’s access, or whether access to your CUI would show up in a log, that’s the place to start. Our team works with manufacturers in the DoD supply chain on exactly this kind of practical, right-sized program. 

Schedule a free consultation with our team to talk through where your insider threat controls stand today. 

 FAQs

What is the goal of an insider threat program? 

To prevent insider incidents, or catch them early, and to manage the response when one occurs. Both intentional harm and accidental harm are in scope. 

Is an insider threat program required for CMMC? 

CMMC Level 2 requires insider-threat awareness training (based on NIST SP 800-171 control 3.2.3) plus related personnel controls like screening and termination procedures. It doesn’t require a formal insider threat program in the way the NISPOM does for cleared contractors. Assessors do look at insider threat policy and procedures alongside training materials, so write your approach down. 

What type of assessment helps identify insider threats? 

Two kinds. A behavior-based threat assessment looks at concerning behaviors and decides whether a person of concern has the interest, motive, and ability to cause harm, which CISA describes as the basis for assessments. A program-level assessment, one of several security assessments you can run, checks how mature your overall program is. CISA publishes an Insider Risk Mitigation Program Evaluation tool for that purpose, and cleared contractors perform a formal self-inspection at least annually. 

Who is the Insider Threat Program Senior Official? 

For cleared contractors, the ITPSO is the cleared official the senior management official appoints in writing to establish and execute the insider threat program. If the ITPSO isn’t also the Facility Security Officer, the FSO must be an integral member of the insider threat team. 

Do small manufacturers need an insider threat program? 

Cleared contractors must maintain insider threat programs; CUI handlers need awareness training and controls; others should adopt safeguards.