Cybersecurity Teams: An Introduction to Blue Team

Blue Team

There are three widely recognized cybersecurity teams: Red, Blue and Purple.

  • Red Team: Offensive Security 
  • Blue Team: Defensive Security 
  • Purple (team/function): the interaction between offensive and defensive teams.

A Red Team aims to emulate threat actors, and their Tactics, Techniques and Procedures (TTPs) to see if the Blue Team is able to detect and respond to these threats. The main goal of Red Team is to improve an organization’s defensive capabilities- their Blue Team. The Blue Team defends against real or simulated attacks.  

NIST provides this definition of Blue Team:  

A group of individuals that conduct operational network vulnerability evaluations and provide mitigation techniques to customers who have a need for an independent technical review of their network security posture. The Blue Team identifies security threats and risks in the operating environment, and in cooperation with the customer, analyzes the network environment and its current state of security readiness. Based on the Blue Team findings and expertise, they provide recommendations that integrate into an overall community security solution to increase the customer’s CS readiness posture. Often times a Blue Team is employed by itself or prior to a Red Team employment to ensure that the customer’s networks are as secure as possible before having the Red Team test the systems. 

NIST’s definition shows that Blue Team provides a variety of defensives services: network vulnerability evaluations, mitigation recommendations, real time threat detection, and overall readiness assessments. These actions include: security monitoring, security control recommendations, threat hunting, and forensics. Both Red and Blue Teams are pit against each other but share the same end goal of improving an organization’s security readiness. This shared end goal means that strong Red and Blue Teams should effectively communicate with each other (and the Purple team facilitators) to ensure security threats are appropriately shared and remediated.

Blue Team’s detection capabilities improve when they learn about Red Team methods. Learning about Red Team exploits and tools improves a Blue Team’s ability to detect these exploitation attempts in network traffic.   Blue Teams use network monitoring tools to check for unusual activities. Unusual network activity could include suspicious user login attempts due to frequency or location, larger than usual file transfers, or network services used after business hours. Blue Teams capture network traffic to analyze for unusual activities and conduct internal and external vulnerability scans to prevent Red Teams from exploiting their network environments.  Effective Blue teams use a variety of tools and policies to prevent and detect attacks like: endpoint security for external devices, up to date antivirus software, properly configured firewalls and network services, IDS and IPS software, SIEM solutions, and vulnerability scanners. Red Teams help Blue Teams recognize the gaps in their defensive posture and improve the use these security tools and policies. The more that Blue Teams continually learn about new defensive and offensive methods the better prepared organizations will be to defend against real attacks.