CMMC Cyber Incident Response: What Contractors Need to Know

EXECUTIVE BRIEF

As cyber-attacks increase globally, cybersecurity regulations are increasingly emphasizing cyber incident response. DFARS, NIST, and CMMC are no exception. 

Here is what defense contracts need to know about cyber incident response requirements: 

• Level 2 contractors need to develop a cyber incident response plan, document and report cyber incidents to internal and external authorities, and test their response capabilities
• Cyber-attacks include but are not limited to ransomware, unauthorized access to systems, and data breaches exposing CUI
• DFARS 252.204-7012 requires contracts to report cyber incidents within 72 hours

Dig deeper and continue learning below!

The stakes for cybersecurity have never been higher, especially for organizations handling sensitive information for the Department of Defense (DoD). Cyber attacks against organizations in the defense sector, many of which are small to mid-sized businesses, are on the rise. In fact, roughly 80% of organizations involved in aerospace, defense, and other critical infrastructure have experienced a cybersecurity breach in the last year. 

A single cybersecurity incident can disrupt operations, compromise national security, and jeopardize vital contracts—especially for smaller organizations. That’s why following a strict protocol for incident response is both a critical Cybersecurity Maturity Model Certification (CMMC) requirement and a strategic business imperative. An effective incident response plan empowers organizations to detect, contain, and recover from threats quickly, minimizing damage and maintaining mission readiness. 

This guide will thoroughly examine CMMC’s incident response expectations, clarify the required maturity levels, and equip you with practical steps to develop a plan that safeguards your competitive edge and operational integrity.

The 5 Steps of the NIST Framework for Incident Response at CMMC Level 1, CMMC Level 2, and CMMC Level 3

The scope of incident handling under CMMC depends on your certification level, which is dictated by the sensitivity of the data your organization handles.   

• CMMC Level 1 requires basic safeguarding to secure Federal Contract Information (FCI) but does not address Controlled Unclassified Information (CUI).  
• CMMC Level 2 introduces incident response requirements derived from NIST SP 800-171 for organizations handling CUI, including establishing an incident response capability (3.6.1), detecting and reporting events (3.6.2), and developing and implementing responses (3.6.3). See more on these in the section below.
• CMMC Level 3 builds on Levels 1 and 2 with enhanced directives from NIST SP 800-172 aimed at combating advanced persistent threats (APTs) through elevated incident management protocols. Level 3 includes requirements to perform post-incident reviews (3.6.4) and test your organization’s incident response capability (3.6.5).

Here’s the breakdown of the specific controls across Levels 2 and 3.

Level 2 (NIST 800-171A rev2)

Establish an Incident Response Capability (3.6.1)  

Organizations must document an incident response plan (IRP) capable of identifying, reporting, and addressing security incidents. Tasks include setting up a response team, defining clear procedures, and integrating tools for real-time monitoring and mitigation.  

Detect and Report Events (3.6.2)  

This control focuses on implementing mechanisms (like SIEM systems or intrusion detection tools) to monitor, detect, and report suspicious activities. Employees must also be trained to escalate anomalies promptly.  

Test incident response capability (3.6.3)  

Having a response capability is one thing, but executing it is another. Organizations must demonstrate its IRP has been tested using tabletop exercises, simulated attacks, and audits to ensure the plan works as intended under real-world conditions. This proactive evaluation identifies vulnerabilities in your response system.   

Level 3 (NIST 800-172)

implement a security operations center (soc)(3.6.1e)  

To ensure your organization has the ability to monitor and defend against cyber-attacks on an ongoing basis, implementing and maintaining a SOC is key to protecting your business and your sensitive information. Your SOC can be established in-house or can be outsourced to a third-party vendor.

Establish a cyber incident response team (3.6.2e)  

Equipping your business with the appropriate software and hardware is the first step, but now you need a team of experts who can assess, document, and respond to cyber incidents within the required time period.

Types of Incidents That Must Be Reported under CMMC

Under CMMC, reportable incidents include any event affecting the confidentiality, integrity, or availability of FCI or CUI. Some common reportable incidents are:  

• Phishing attempts  
• Unauthorized access (e.g., login from unrecognized devices or IPs)  
• Cyberattacks such as ransomware, DDoS, or advanced malware campaigns  
• Data breaches exposing CUI  
• Malware outbreaks within organizational systems  

Be sure to report incidents  to the DoD within 72 hours as required by DFARS 252.204-7012.

Who’s Responsible for Incident Response in an Organization Seeking CMMC Compliance?

Each organization must define roles and responsibilities clearly to handle incident response effectively. Typical roles include:

• Incident Response Team (IRT): A designated team responsible for detecting, reporting, and mitigating incidents.  
• Chief Information Security Officer (CISO): Oversees broader cybersecurity strategy and ensures compliance with CMMC requirements.  
• IT and Security Personnel: Maintain monitoring tools, provide technical fixes, and execute containment strategies.  
• Leadership/Management: Responsible for timely reporting to DoD and stakeholders and ensuring compliance through organizational policies.  

Smaller organizations—without dedicated IT or security teams—can outsource to Registered Provider Organizations (RPOs) specializing in CMMC compliance. ISI, for instance, offers comprehensive incident response management tailored for DoD contractors.

Key Components of a CMMC Incident Response Plan

To build a compliant Incident Response Plan (IRP), you need to focus on the following five components.

1. Develop an Incident Response Policy

Your IRP should start with a formal policy outlining your approach to identifying and mitigating cyber incidents. This policy should align with NIST guidance and include provisions for roles, response goals, response processes, and mitigation timelines. 

2. Implement Incident Detection & Reporting

Implement robust real-time monitoring systems to detect intrusions, unauthorized access, or malicious activity. Your tech stack should include email security tools, firewalls, and behavioral anomaly detection. Regular training should empower employees to spot and report social engineering tactics like phishing. 

3. Develop and Implement Response Procedures

Create a step-by-step playbook for responding to various types of incidents (e.g., ransomware, malware, unauthorized access). This should include containment, forensic investigation, eradication of the threat, and restoration of affected systems. 

4. Conduct Post-Incident Reviews

Once an incident has been resolved, conduct a detailed review with all team members involved. Focus on answering questions like:

• What went wrong, and why?  
• What processes or tools failed?  
• How can we improve our response capabilities going forward? 

5. Test the Incident Response Plan

CMMC requires regular incident response testing of your capabilities. By conducting tabletop exercises and simulated breaches, you can identify weaknesses, validate procedures, and ensure readiness.

Reporting Requirements for CMMC Incident Response

Under DFARS 252.204-7012, DoD contractors must report cyber incidents affecting CUI or FCI to the Defense Industrial Base Cybersecurity (DIBNet) portal within 72 hours. Organizations must also preserve forensic data for at least 90 days for potential follow-up investigations. The reports should include a detailed account of the incident timeline, affected systems, and mitigation measures taken. 

How Small Businesses Can Comply with CMMC Incident Response Requirements

For small businesses with limited IT budgets or expertise, implementing CMMC-compliant organizational incident response capabilities may seem daunting. However, there are strategies to simplify the process, including:

• Partner with RPOs: Companies like ISI provide incident response templates, risk assessments, and continuous monitoring to ensure compliance.  
• Leverage Automation: Use automated tools for intrusion detection and real-time reporting to reduce human error.  
• Cloud-Based Solutions: Managed SIEM services and secure cloud infrastructure can reduce operational overhead and include data backups while meeting security controls.  
• Templates and Policies: Pre-designed templates can fast-track your policy and response procedure documentation and save time. 

Work with ISI for CMMC Compliance Success

Achieving CMMC compliance is complex, but ISI can make it manageable. With nearly 15 years of experience assisting DoD contractors, we’re uniquely positioned to help you build a robust CMMC-compliant incident response plan.  

Our services include developing incident response strategies, conducting risk assessments, and effectively training your team to handle cyber threats. Whether you’re at Level 1 or preparing for Level 3, we have the resources and expertise you need.    

FAQs about CMMC Incident Response

How Does CMMC 2.0 Affect Incident Response Requirements?

CMMC 2.0 consolidated the model into three levels. Level 1 requires basic safeguards, while Levels 2 and 3 mandate robust incident response procedures, including comprehensive detection, reporting, and post-incident analysis. 

How Often Should You Test Your CMMC Incident Response Capabilities?

Incident response plans should be tested at least annually, with additional tests after any significant system changes or incidents. 

Who Is Responsible for Incident Response within a CMMC-compliant Organization?

The responsibility typically lies with an Incident Response Team (IRT), overseen by the CISO or equivalent role. Outsourcing to an RPO like ISI can also fulfill these responsibilities.