CSIRT: respond to IT incidents to protect the business

Estimated reading time: 6 minutes

Introduction

In recent years, cybersecurity has become a priority for all companies of all sizes. Cyber attacks are increasingly sophisticated and can cause serious damage, both economic and reputational. To protect themselves from attacks, companies must adopt 360-degree cybersecurity solutions, which include not only prevention tools but also incident detection and response tools.

In this context, the CSIRT (Computer Security Incident Response Team) plays a key role. But what exactly is a CSIRT and how can it help a business deal with cyber incidents?

What is a CSIRT?

CSIRT stands for Computer Security Incident Response Team. It is an organizational structure dedicated to the management of cyber incidents within a company or organization.

The CSIRT is tasked with preventing, detecting, analyzing and responding to security breaches or other IT events that may put company systems and information at risk.

In essence, the CSIRT constitutes the first level of response to cyber incidents that may occur within an organization. Thanks to the CSIRT, companies can address these incidents quickly and effectively, mitigating the damage and avoiding potential data breaches.

Tasks and activities of a CSIRT

The main tasks of a CSIRT are:

• Monitoring: The CSIRT constantly monitors the corporate IT infrastructure to identify emerging threats and detect potential security incidents. This activity is performed through tools such as IDS/IPS, SIEM, endpoint detection systems and threat intelligence.
• Investigation: Once a potential incident is detected, the CSIRT immediately initiates investigation procedures to determine its severity and origin. This phase includes digital forensics, malware analysis and event correlation activities.
• Containment: after analyzing an incident, the CSIRT implements all the necessary measures to contain it and prevent it from spreading further in the corporate IT system. For example, it can isolate malware or lock down a compromised account.
• Ripristino: il CSIRT lavora per ripristinare i sistemi e i servizi colpiti da un incidente, minimizzando i tempi di inattività. For example, it can reinstall compromised servers or recover data from backups.
• Communication: During and after an incident, the CSIRT coordinates closely with senior management, IT managers, and external entities such as law enforcement. Transparent and timely communication is essential.
• Prevention: Based on the lessons learned from each incident, the CSIRT identifies proactive measures to strengthen security and prevent similar attacks from happening again.

To carry out these activities effectively, the CSIRT uses a wide range of technological tools, as well as solid know-how in the field of cybersecurity.

Organizational models of a CSIRT

CSIRTs can be organized according to different models, based on the size and specific needs of each company:

• Internal CSIRT: In-house IT security team dedicated to incident management. It is the most common model in large companies.
• External CSIRT: service provided by an external company specialized in cybersecurity incident response. Useful for SMEs.
• National CSIRTs: Government teams that support critical infrastructure protection nationwide. For example, the CSIRT Italy.
• CERT: Traditional model with a focus on researching and sharing vulnerability information.

Regardless of the model, it is critical that the CSIRT is well integrated with the company’s IT and business processes. Must also follow established best practices for handling cyber security incidents.

Why get a CSIRT?

Having a CSIRT brings numerous advantages to companies, including:

• Rapid incident response: CSIRT allows you to detect and analyze attacks in a very short time, limiting the damage.
• Business protection: CSIRT minimizes the impact of incidents and downtime of systems and services.
• Regulatory Compliance: The CSIRT helps ensure compliance with cybersecurity and privacy regulations such as GDPR and NIS.
• Sharing of knowledge: the CSIRT disseminates a culture of safety in the company and shares the lessons learned from each incident.
• Cost reduction: Rapidly detecting and containing incidents can significantly reduce the costs associated with data breaches.
• Reputation: An effective CSIRT conveys an image of trustworthiness to customers and business partners.

How to implement an effective CSIRT

To implement a truly effective and integrated CSIRT in business processes, it is important to follow some best practices:

• Create a clear governance model with well-defined roles and responsibilities
• Establish robust operational processes and procedures, based on established frameworks (e.g. NIST)
• Equip the CSIRT with adequate human resources, with technical skills and soft skills
• Ensure full collaboration between CSIRT and IT, Infosec and business continuity top management
• Invest in cutting-edge technologies for incident detection, analysis and response
• Promote a culture of safety and continuous improvement in the company
• Participate in cyber threat information sharing communities
• Plan training activities, exercises and simulations to test the capabilities of the CSIRT

The CSIRT in action: tools and activities

Let’s now look in more detail at some of the key tools used by CSIRTs and the typical activities performed in the different stages of managing an IT security incident.

Tracking and tracking

To identify indicators of compromise and detect incidents early, CSIRTs use:

• SIEM: correlate and analyze in
• real-time events and logs from different sources. Detect anomalous activity.
• IDS/IPS: monitorano il traffico di rete intercettando attacchi come exploit, malware e DDoS.
• Endpoint Detection and Response (EDR): Monitor endpoints, servers, IoT devices for malware, targeted attacks, and anomalous behavior.
• Threat Intelligence: Constantly updated feeds with IOCs (Indicators of Compromise) to detect known threats and new attacker TTPs (Tactics and Techniques).
• Honeypots and deception technologies: trick attackers into believing they have compromised valuable assets.
• Vulnerability assessment: scansioni periodiche di sicurezza per identificare vulnerabilità da patchare.

Analysis and containment

Once a potential incident is detected, the CSIRT carries out a thorough investigation using:

• Digital forensics: acquisition and forensic analysis of disks, memory and logs to reconstruct the “crime scene”.
• Reverse engineering malware: Malware code analysis to understand offensive capabilities.
• Network traffic capture and analysis: Capture and analyze network traffic to identify anomalous connections.
• Threat hunting: proactive search for intrusions and lateral movements of attackers within the network.

To contain an incident, the CSIRT can:

• Isolate and shut down compromised systems
• Revoke privileges and change passwords
• Block malicious accounts, IP addresses, domains
• Stop malicious services and processes
• Delete infected files from systems

Information recovery and sharing

In the recovery phase, the CSIRT:

• Restore compromised systems via clean reinstallation
• Recover whole data from backups
• Reconfigure network and security devices
• Recheck the entire infrastructure to rule out further compromises

Post-incident, share insights via internal reports and threat sharing platforms to prevent a repeat of the attack.

Conclusion

We’ve seen what CSIRTs are, what their main tasks are, and how they can help a business detect and deal with cybersecurity incidents quickly and effectively.

Having a CSIRT, internal or external, has become essential for any organization that wants to protect its digital assets and business continuity. However, to reap the maximum benefits from a CSIRT it is important to integrate it into business processes and equip it with adequate resources and skills.

Safety is never a goal, but a continuous path. For this reason, in addition to a CSIRT, it is important for companies to adopt proactive prevention solutions such as [EDR] and specialized threat detection and response services provided by companies such as [NOI]. It’s never too late to raise your level of cyber-resilience!

Useful links:

• How to manage the “right boom” after a security incident with Log Management, IT monitoring and SOCaaS services
• UEBA: Behavior analysis explained
• Examples of phishing: the latest campaigns mentioned by the CSIRT
• CTI (Cyber Threat Intelligence): How does it work?