Computer Emergency Response Team (CERT) or Computer Security Incident Response Team (CSIRT) are well-known acronyms that represent expert groups for assistance in resolving or diminishing consequences of computer security incidents for their users. In order to decrease a risk of computer security incidents, CERT/CSIRT teams provide preventive and educational services to their users, and issue security warnings on known vulnerabilities and threats to computer systems.

Information Systems Security Bureau is constantly developing its own capabilities, and is prepared to offer its users all functionalities and services of CERT/CSIRT team at any time. Information Systems Security Bureau participates under the name CERT ZSIS in the work of international organizations, associations and exercises.

CERT ZSIS participates in organization and implementation of international exercises on cyber security, such as Cyber Coalition organized by the North Atlantic Treaty Organization (NATO). CERT ZSIS participated in Cyber Coalition in 2010 and 2011 as an observer, and since 2013 as a direct participant. After Croatia’s membership in European Union CERT ZSIS is participating in planning and implementation of Cyber Europe exercise organized by the European Union Agency for Network and Information Security (ENISA).

Since 12 July 2009 CERT ZSIS is a full member of Trusted Introducer, which gathers mostly European CERT/CSIRT teams and represents a platform for exchange of knowledge and experience in handling computer security incidents. Service Trusted Introducer is held by TF-CSIRT working group within a scope of the European academic and research network GÉANT.

Since 27 June 2012 CERT ZSIS is a full member of FIRST organization, a world's association of CERT/CSIRT teams which, as Trusted Introducer, represents a platform for promotion of knowledge on computer security incidents management in a wider international environment.