Blue Team
A blue team is the defensive security group within an organization responsible for detecting, preventing, and responding to cyberattacks and security incidents.
The blue team represents the defensive side of an organization's cybersecurity operations. Blue team members are responsible for maintaining the security posture of an organization by monitoring for threats, investigating suspicious activity, and responding to incidents. They work to strengthen defenses, improve detection capabilities, and ensure that security controls are effective against both known and emerging threats.
Blue team responsibilities span a wide range of activities, including security monitoring through SIEM platforms, intrusion detection and prevention, log analysis, threat hunting, incident response, forensic investigation, and vulnerability management. Team members use a variety of tools including endpoint detection and response (EDR) solutions, network monitoring platforms, threat intelligence feeds, and security orchestration, automation, and response (SOAR) systems.
Effective blue teams operate proactively rather than just reactively. Threat hunting involves actively searching for indicators of compromise (IOCs) and signs of adversary activity that may have evaded automated detection. Blue teams also conduct regular reviews of security controls, update detection rules, and perform tabletop exercises to refine incident response procedures.
In the context of red team versus blue team exercises, the blue team defends the organization against simulated attacks. The insights gained from these exercises help blue teams identify detection gaps, improve response times, and strengthen security controls. Many mature organizations now favor purple team approaches where red and blue teams collaborate openly to maximize learning and improve defenses more rapidly.