CERT vs. CSIRT vs. SOC: What's the difference?

CERT vs. CSIRT vs. CIRT: What do they stand for?

The following terms describe common organizational models of incident response teams:

• CERT stands for computer emergency response (or readiness) team.
• CSIRT stands for computer security incident response team.
• CIRT can stand for computer incident response team or cybersecurity incident response team.

Bear in mind that just because two organizations call their response teams a CSIRT doesn't mean those two teams conform to some idealized definition. In fact, they might not have the same goals, use the same methods or have equivalent scope.

In practice, CSIRT, CERT and CIRT are used interchangeably. In fact, CSIRT and CIRT are almost always synonymous.

These terms essentially refer to the team members, processes, duties and responsibilities for incident response within an organization. The specific form this takes varies from company to company. In some cases, it might include monitoring for incidents -- i.e., threat hunting, continuous monitoring, operational security oversight, etc. -- as well as responding to an incident once detected. In other cases, it might include only the response elements and not the detection and monitoring work.

What is CERT?

Although many companies use the term CERT generically, it has been a registered mark of Carnegie Mellon University since 1997. Companies can apply for authorization to use the CERT mark. Companies that are not authorized to use the term should have a candid conversation with legal counsel before using it in a commercial context, such as for a consulting service or product offering in a managed security service. It might be prudent to have a conversation even when using the term for an internal team name, depending on how public-facing the team is.

Part of the challenge with organizations using the name CERT internally is that it can be confusing. Is it used as a synonym for CSIRT? Or is the organization trying to convey something else? Both can be true depending on context.

For example, Carnegie Mellon's CERT has a particular focus and niche. It operates as a "partner with government, industry, law enforcement and academia to improve the security and resilience of computer systems and networks." It studies "problems that have widespread cybersecurity implications and develop[s] advanced methods and tools."

Some organizations reflect this nuance in the way they use the term. For example, the team might place greater emphasis on partnerships with other internal or external teams and organizations. Or maybe it has increased focus on methodology and development of tools designed to forecast problems before they arise. Or maybe it focuses on emerging threat research, such as adversary methodology or tradecraft.

Other organizations, especially those unaware that the term is a registered mark, might simply use CERT as a synonym for CIRT or CSIRT.

Forming an incident response team

Practitioners should understand that there is fluidity in how organizations use these terms. CERT, CSIRT and CIRT groups can exist as permanently staffed groups or as teams assembled in response to a security incident. The scope can include any number of environments, either alone or in combination. For example, on-premises data centers -- either virtual or physical; corporate campus networks; cloud environments; production environments used by customers -- and thereby including containers and container orchestration; and numerous other scenarios.

An array of specialists and practitioners can support the function. For example, an organization developing machine learning and AI components might include machine learning engineers or data scientists on the response team. Another organization might have specialists in operational technology for industrial equipment.

Regardless of team composition, the focus is almost always on establishing incident response capabilities. That means preparing for incidents, identifying and evaluating incidents when they occur, responding to and mitigating incidents, and recovering from incidents. Those elements of incident response are outlined in detail in NIST Special Publication (SP) 800-61 Rev. 3, a document worth reviewing when developing an incident response plan and forming a team.

Note that a CSIRT at one organization might have response processes that align with NIST's guidance but that are heavily supported by AIOps. Another company might see the role of its CSIRT as focused entirely on policy. A third might look for signs of compromise in log files and security monitoring tools such as a SIEM system or a security data lake.

How is a SOC different from CSIRTs, CERTs and CIRTs?

A security operations center (SOC) typically encompasses multiple aspects of security operations, while CSIRTs, CERTs and CIRTs focus specifically on incident response.

A SOC's purview can include the incident response function -- either in whole or in part -- as well as other tasks. For example, a SOC can:

• Monitor operations and controls. Traditionally, that meant deploying intrusion detection, intrusion prevention and SIEM tools. Now, a SOC might use cloud-native alerting platforms, cloud security posture tools and AI.
• Oversee evaluation of operational and security telemetry and information gathering.
• Manage operational tasks such as identity management; rule set maintenance for firewalls or cloud filters -- for example, security groups; forensics and investigation support; or any other aspect of operational security.

A SOC's monitoring efforts likely extend beyond incident response. A SOC might harvest and collect metrics to support customer service or service delivery -- at a managed security service provider, for example -- or it might support management reporting, such as preparation of metrics and data to support risk assessment or for audit support.

While a SOC often comes up in the context of incident response, it almost always has other elements of security within its scope of responsibility. A SOC is likely to have a broader operational purpose and scope than a CSIRT or CIRT. The specifics depend on the organization.

Should an organization implement a CERT, CSIRT, CIRT or SOC?

Organizations need to decide which type of incident response team is right for them. The choice should be based on specific goals, structure and resources. For example, there might be advantages to creating a SOC if monitoring is paramount and the organizational structure is conducive to centralization at a single physical or logical location. Virtual SOC and distributed SOC are both viable models. Centralization can deliver economies of scale and a simplified reporting hierarchy.

If an organizational structure is more decentralized, or otherwise not conducive to the centralization of monitoring and other security operations, a CSIRT might make more sense. It's important to evaluate the relative advantages of both, understand the organization's needs and select the approach that's optimal for the business.

Help is out there. Organizations should consult the many available resources to guide their efforts in forming a response team, including the following:

• NIST SP 800-61. Published by the U.S. federal government, this guide is aligned with the NIST Cybersecurity Framework.
• ISO/IEC 27035:2023. This is a multivolume set of international standards for information security incident management.
• FIRST, Forum of Incident Response and Security Teams, CSIRT Services Framework. This comprehensive document describes the services and capabilities that response teams can provide.
• European Union Agency for Cybersecurity (ENISA) Good Practice Guide for Incident Management. This comprehensive incident response resource includes a code of practice -- Annex II -- as well as sample workflows, organizational frameworks, processes, communication guidance and other information specific to a European audience.

Ultimately, it matters less what the response team is called -- whether CERT, CSIRT, CIRT or something else -- and more that what's built will deliver when needed.

Ed Moyle is a technical writer with more than 25 years of experience in information security. He is a partner at SecurityCurve, a consulting, research and education company.