The United States government has received aggressive cyber-attacks in recent years.  

Statistics show that the US was the country most targeted by hackers between July 2020 and June 2021, accounting for 46% of all cyber-attacks reported globally. Most of these attacks target critical infrastructures across several federal agencies, with the Department of Defense (DoD) recording many breach attempts.  

The SolarWinds cyberattack in 2020 is perhaps the biggest cybersecurity breach to have targeted the US federal systems in the recent past. This attack happened when hackers embedded malicious code into the SolarWinds Orion software during the program’s routine update.  

As a result, millions of government and enterprise network data slipped into the wrong hands. That includes sensitive defense information since the DoD is a federal agency that relies on this software tool.  

To mitigate the repercussions of similar attacks, the Department of Defense implemented sweeping reforms to its previous CMMC program. The revised framework, which took effect on December 16, 2024, introduces mandatory C3PAO assessment for defense contractors seeking CMMC Level 2 compliance.  

But who are C3PAOs, and how do they differ from 3PAOs? This blog shall conclusively address that question. 

What Are C3PAOs? 

C3PAOs is an acronym for CMMC Third-Party Assessor Organizations (C3PAO). They’re critical agencies or personnel within the CMMC ecosystem tasked to conduct and compile cybersecurity audit reports on behalf of organizations seeking CMMC certification (OSCs).  

C3PAOs are accredited by the Cyber AB, the official CMMC authorization body.  

C3PAOs are mainly required for CMMC Level 2 audits. However, they play an indirect role in assessing compliance across the other levels in the CMMC framework.  

To discharge their mandate more effectively, CMMC third-party assessor organizations work hand in hand with Certified Professionals (CPs) and Certified Assessors (CAs). These personnel may be directly employed by a C3PAO or contracted on a need basis.  

Unpacking CMMC 

It’s difficult to fully grasp the role of CMMC third-party assessor organizations before understanding CMMC and how its new framework is structured.  

CMMC is a common abbreviation for the Cybersecurity Maturity Model Certification. It’s a certification framework designed by the Department of Defense to evaluate the extent to which defense contractors comply with certain cybersecurity controls published by the National Institute of Standards and Technology (NIST).  

The CMMC program obligates Defense Industrial Base (DIB) companies to comply with all the specified cybersecurity standards. By adhering to the defined protocols, the DoD can safeguard Controlled Unclassified Information (CUI) and Federal Contract Information (FCI) across networks that handle such information.  

To achieve compliance, OSCs must verify that their information systems, which handle CUI and FCI, comply with CMMC’s mandatory security controls. While organizations can self-assess for CMMC Level 1 compliance, Level 2 audits should strictly be undertaken by a licensed C3PAO. 

What Are 3PAOs? 

3PAOs are third-party assessor organizations that also play a pivotal role in safeguarding cybersecurity across the defense supply chain.  

However, unlike C3PAOs authorized by the CMMC AB, 3PAOs operate within the Federal Risk and Authorization Management Program (FedRAMP). Their core mandate is to evaluate the cybersecurity of Cloud Service Offerings (CSOs). 

More About FedRAMP 

The Federal Risk and Authorization Management Program is a US federal program that publishes the standards for assessing and monitoring cloud-based products and services.  

FedRAMP authorizes CSOs either through a Joint Authorization Board (JAB) or via independent agencies, with 3PAOs playing a particularly important role in the latter. 

Similarities Between C3PAOs and 3PAOs 

C3PAOs and 3PAOs are both independent cybersecurity auditors. Therefore, their assessment reports are mostly unprejudiced.  

The two assessor organizations are also answerable to federal agencies rather than those they audit. This arrangement eliminates conflicts of interest, allowing them to provide accurate and verifiable cybersecurity assessments.  

Another noticeable similarity between CMMC 3PAOs and 3PAOs is that they conduct periodic assessments to ensure organizations fully comply with relevant cybersecurity controls. Their findings inform the federal government’s risk-based decisions for issuing defense contracts or using CSOs, respectively. 

Differences Between C3PAOs and 3PAOs

1. Roles and Responsibilities

C3PAOs

As hinted, CMMC 3PAOs are mandated to undertake CMMC compliance audits for OSCs.  

These agencies mainly assess the cybersecurity posture for organizations seeking compliance with CMMC Level 2 certification. They then report their findings to Cyber AB, determining whether to issue certification to the audited company.  

C3PAOs also play an indirect but essential role in CMMC Level 3 compliance.  

OSCs aiming for CMMC Level 3 certification must have their cybersecurity architectures assessed by government-appointed auditors. However, such organizations must attain Level 2 certification after undergoing C3PAO audits.  

It’s also worth pointing out that any organization, not necessarily defense contractors, can enlist CMMC 3PAO services to assess their cybersecurity postures.  

3PAOs 

3PAOs audit organizations for CSP issuance. They certify that a vendor’s existing cybersecurity infrastructure complies with the control requirements stipulated in FedRAMP.  

3PAO audits primarily entail reviewing artifacts, which are documents in an organization’s CSP security package.  

The assessors also evaluate the overall cybersecurity posture of the vendor’s cloud ecosystem and recommend proper interventions to seal any identified gaps. 

2. Working Methodology

C3PAOs 

A CMMC C3PAO cybersecurity audit begins when an organization seeking certification contacts an authorized C3PAO to have its cybersecurity network audited.  

The OSC must specify the critical assets their information systems handle, including CUI and FCI assets. Others are security protection assets and contractor risk-managed assets.  

Upon receiving the preliminaries, a C3PAO will assemble its assessment team. The team typically consists of a lead assessor, a secondary assessor, and quality assurance personnel.  

Next, the assessment team will review the OSC’s security assets to ensure compliance with CMMC’s new rule updates. They may also interview the vendor’s employees, suppliers, and other stakeholders to ensure every piece of information checks out.  

A C3PAO will now conduct practical tests to ensure the OSC’s cybersecurity framework perfectly aligns with CMMC’s mandatory controls. They then report to Cyber AB whether the contractor has MET or NOT MET the CMMC’s standards.  

Conditional CMMC compliance certification may be issued, granting the tested organization a 180-day window to address all the shortfalls in the audit report. 

3PAO 

3PAOs also follow a rather straightforward audit process. The assessment typically starts by scoping a vendor’s cloud environment for gaps and vulnerabilities.  

Next, the 3PAO prepares two critical documents – the Security Assessment Plan (SAP) and the Security Assessment Report (SAR).  

The SAP lists the various assets within the assessment scope. These typically include computing hardware, software, physical equipment, and facilities. Meanwhile, the SAR details the threats and vulnerabilities unearthed during the assessment.  

Other critical 3PAO assessment documents include the Systems Security Plan (SSP) and the Readiness Assessment Report (RAR).  

With all essential documents, 3PAOs can now get down to work. CSO audits may last a couple of days or several weeks, depending on the assessment scope undertaken.  

Most 3PAOs will start with manual control testing to ensure your CSO networks meet FedRAMP requirements. They’ll then follow with vulnerability scanning and penetration testing, the latter of which entails simulating real-life cyber-attacks to gauge your defense capabilities.   

After conducting extensive audits of a vendor’s cloud service offering, a 3PAO will issue a comprehensive report highlighting the organization’s compliance status with FedRAMP controls. They may subsequently perform additional retests and updates as JAB reviewers advise.

3. Qualifications

C3PAO 

To become a qualified CMMC C3PAO, you must express your interest through the CMMC AB by filling out a detailed application form on its website.  

The agency will screen your application to prequalify you for the next stage. Dunn and Bradstreet (D&N) conduct much of the screening on behalf of CMMC AB, a rigorous process that involves scoring applicants based on their technical CMMC and cybersecurity knowledge.  

Some of the prerequisites here include; 

• Certificate of completing CMMC Level 3 assessment 
• Evaluating any third-party cloud services used by your organization 
• ISO 9001 and ISO 27001 certification 

You must score at least a “Moderate” to proceed to the next steps.  

If you fortunately make the cutline, you’ll be subjected to a Foreign Ownership, Control, or Influence (FOCI) assessment to establish any potential conflict of interest with foreign actors. The FOCI evaluation is more intense if you’re an Employee Stock Ownership Plan (ESOP) organization or a global partnership with headquarters in the US.  

If you pass FOCI’s assessment, Cyber AB will forward your information to the DoD for subsequent evaluations and possible accreditation.  Accredited CMMC 3PAOs are listed on the Cyber AB website.  

3PAOs 

3PAOs also undergo a rigorous certification process to be authorized.  

First, interested 3PAOs must spend a minimum of a year in the Cybersecurity Inspection Body Program to gain basic technical competencies. The applicant is then subjected to intense screening by the American Association for Laboratory Accreditation (A2LA).  

Among the key requirements include; 

• Undertaking proficiency tests administered by the Baltimore Cyber Range (BCR) 
• At least four hours’ worth of Continuing Professional Education (CPE) or its equivalent 
• (ISO/IEC) 17020 certifications 
• Proof of technical competencies in the Federal Information Security Management Act (FISMA) 

A list of certified 3PAOs is available on the FedRAMP marketplace.  

Final Word 

Both C3PAOs and 3PAOs play critical roles in safeguarding the federal supply chain from malicious cybersecurity attacks. However, the two assessment organizations differ primarily in the types of programs they work with.  

A C3PAO will suit you best if you seek CMMC certification, particularly Level 2 compliance. On the other hand, a 3PAO would be ideal if you’re seeking CSO compliance certification.  

The good news is that the Department of Defense has simplified the compliance process for defense contractors. Simply define the nature of sensitive federal information your organization handles to understand whether you require a C3PAO or 3PAO audit.