What Is a Blue Team?

Blue Team Definition:

During cyber security testing engagements, blue teams evaluate organizational security environments and defend these environments from red teams. These red teams play the role of attackers by identifying security vulnerabilities and launching attacks within a controlled environment. Both teams combine to help illuminate the true state of an organization’s security.

The idea that you can better understand your defenses by attacking them in a controlled environment is a long-established military principle. This idea is most commonly expressed in the practice of “red teaming,” where an outside group of independent actors tests the systems or defenses of a target organization to identify any existing vulnerabilities.

In the world of information security, the practice of red teaming is now well established. Red teams, who act as “ethical hackers,” methodically study an organization’s structure and defenses and then launch attacks to exploit any weaknesses.

Yet red teams are only part of the equation. On the other side stand “blue teams” — security professionals who are tasked with defending an organization’s systems and assets against attacks, both real and simulated.

Red Team vs. Blue Team Exercises: How They Work

Blue teams conduct operational network security evaluations and provide relevant mitigation tools and techniques for organizations seeking to gauge their defenses or prepare for red team attacks.

Blue teams are often composed of the security personnel within an organization, or that organization may select certain team members to create a dedicated blue team within the department. Blue teams may also be independent consultants hired for specific engagements who use their expertise to help audit the state of an organization’s defenses.

When an organization schedules red team vs. blue team exercises, red teams may attempt a range of techniques to launch a successful attack. These techniques are very open-ended and not always confined to the digital realm.

Red team attacks may include scenarios such as a red team member posing as a vendor to infiltrate the target organization. This person may slip into the room undetected and quietly install malware, gaining network access.

Before getting started, red teams typically engage in digital reconnaissance to evaluate organizational defenses, then deploy various sophisticated attack techniques to compromise the target’s security while avoiding detection.

Blue teams are tasked with rebuffing these attacks and exposing red team activity. This often begins with a detailed risk assessment of the organization’s current security posture. Blue teams then may deploy a combination of human intelligence activity and technical tools to detect and rebuff red team incursions.

Ultimately, a blue team is expected to analyze log data, perform traffic analysis, execute audits, perform digital footprint and risk intelligence analysis, and take other similar steps to prevent any breaches — and then rectify any uncovered vulnerabilities.

The Value of Blue Team Testing

A skilled cyber security blue team can play a critical role in helping to develop a comprehensive plan for organizational defense using the latest tools and techniques — a “blue team security stack,” in other words. Often, it’s best to think of them as the most active contingent of a security team.

Not all security team personnel specialize in tasks that are considered to be high-level or relevant enough for testing. Blue teams are focused on high-level threats and are dedicated to continuous improvement in detection and response techniques.

To succeed, blue teams must be rigorously thorough; after all, red teams can launch 99 unsuccessful attacks and still win on the 100th attempt. Blue teams must be right all the time. In addition to attention to detail, blue teams must also think creatively and have the ability to adapt on the fly. This is because many of the most effective red teamers (and black hat hackers) are remarkably adept at formulating novel and hard-to-predict attack techniques.

By evaluating the work of both red and blue teams, organizations can develop a holistic picture of the state of their security — and make any changes that may be required to ensure a robust overall defense.