The blue team represents the defensive security function within an organisation that are responsible for protecting systems, detecting threats, responding to incidents, and continuously improving security posture.
This team typically includes security operations centre (SOC) analysts, incident responders, security engineers, and threat hunters who work to identify and mitigate cyber threats before they cause damage. The blue team’s responsibilities can include the monitoring of security alerts, analysing logs, investigating suspicious activity, deploying security controls, and developing defensive strategies to counter evolving threats.
In red team exercises, the blue team operates as they normally would where they would be unaware (or only partially aware) that a simulated attack is underway. This tests whether they can detect anomalous behaviour, identify indicators of compromise, and respond effectively to contain the threat.
The insights gained from these exercises can help blue teams refine their detection rules, improve response procedures, and identify gaps in their monitoring coverage. Beyond red team exercises, blue teams engage in ongoing activities like threat intelligence analysis, security control tuning, vulnerability management, and security awareness training aimed at strengthening the organisation’s defensive capabilities against real-world threats.