Nowadays is hard to give strong definitions on what are the differences between Security Operation Centers (SOC), Computer Emergency Response Teams (CERT) and Computer Security Incident Response Teams (CSIRT) since they are widely used in many organisations accomplishing very closed and similar tasks. Robin Ruefle (2007) on her paper titled "Defining Computer Security Incident Response Teams" gave us a nice idea. She also admits there is not such a strong difference between those common terms: CSIRT, CERT, CSIRC, CIRT, IHT. Her conclusion made me thinking about how this topic has been evolving over the past 10 years.
Despite her amazing work on defining CSIRTs I would give you more details on how those teams have been evolving over the past decade based on my personal experiences directly to the field. Indeed after being involved on building several CERTs, organising CSIRTs and evaluating SOCs I started to spot strong and soft similarities between those teams. Today I'd like to share with you those strong and soft similarities without talking about "differences" since there are not evidence on differences at all.
Each team is asked for CyberSecurity incidents but each team holds specific aims and respond to cybersecurity incident in a specific way. Every team needs to understand what happened after a cybersecurity related incident and this is the very strong common point that every team takes care of: deeply understand what happened. Nobody is better then other or nobody is more addicted respect to other in understanding what really happened during an incident, every team have fully autonomy to figure out what happened through inspection and analytical skills. The weak similarities come after the initial analysis phase. CSIR Teams ad SOC Teams usually study the related incident looking for a response while CERT usually tries to forecast incidents. The definition of response highlight the "weak similarities" between CSIRT and SOC.
CSIRT usually look to the incident with a "business" perspective taking care of (but not limited to): communication countermeasures, policy creations, insurance calls, business impact analysis, technical skillset and off course taking care about technical mitigations.
For example a CSIRT would evaluate according to the marketing area a communication strategy after a successful incident hit the company, or it could call insurances to evaluate if they will cover some damages or again it could interact to HR area to define missing skillsets in the organisation. Off course it is able to interact with defensive technologies but it's only one ste of its tasks.
A SOC usually look to the incident with a more "technical" perspective taking care of (but not limited to): incident forensic, log analysis, vendor calls, patch distributions, vulnerability management and software/hardware tunings.
For example after an incident happened to an organisation its SOC would try to block it involving all its resources to block the threat by acting on peripheral devices or running commands directly on user's machines. The SOC deeply understands SIEM technology and it is able to improve it, it is also able to use and to interact through defensive teams and/or technology like sandboxes, proxy, WAF as well. The SOC team holds strong network oriented capabilities.
CER Teams usually take care about incidents following the community sharing procedures such as (but not limited to): feeds, bulletin, Index of Compromises and applying effective governance actions to local IT/SOC teams enabling them to mitigate the incident in the fastest way possibile. CERT team members work a lot with global incidents understanding new threats and tracking known threat movements. They usually work with Threat Intelligence Platforms and with high level dashboard to better understand the evolution of threats to forecast new attacks.
CERTs and SOCs are usually focused on prevention such as (but not limited to):
What are the best rules to apply? What are the procedures in case of incidents?
They are really focused on using threat intelligence in order to spot attack and to block incidents. On the other hand CERTs and CSIRTs are mostly focused on Guidelines and business impact analysis while SOCs and CSIRTs really need to follow incident response procedures in order to apply their high technical skills to mitigate the attack. The following image tries to highlight the main keywords that you would probably deal if you work on a SOC a CERT or in a CSIRT.
The main ideas behind the 3 teams could be summed up in the following terms: Mitigation (belongs to SOC), Response (belongs to CSIRT) and Alerting-Prevention (belongs to CERT). I'd like to point out that mitigation and response are quite different concepts. Indeed mitigation holds a technical view of the resolution, response holds a more business view of the resolution. While mitigating an incident means to "take it down" and so to restore the attacked system as it was before the incident, an incident response could include more sophisticated actions that could include the board of director in the decision process as well.
Similar teams but with strong attitudes need different professional profiles. Usually SOC Teams need more technical profiles which includes hard skills such as: vendor based certifications, network oriented attitudes and forensic attitudes. CSIRT teams needs a mixup profiles more oriented to technical skills but also with business view such as: risk evaluation, guideline buildings and communication skills. CERTs need to have a wide landscape vision about threats and for such a reason they need to know threat intelligence, they need to know prevention tools and to be part of strong IoC sharing communities. Developer skills are not mandatory on those teams but if "weak and dirty" scripting skills are in place, the entire team will benefit from them. Automation and integration are widely needed on such a teams and a scripting profile would create such an integrations.
In ten years things have been changed a lot from the original definitions and it's quite normal being involved in hybrid teams.