Red team vs. blue team testing in cybersecurity

Red team versus blue team exercises simulate real-life cyberattacks against organizations to locate weaknesses and improve information security. The red team are the attackers attempting to infiltrate an organization’s digital and physical defenses. The blue team’s job is to detect penetration attempts and prevent exploitation.

Red team vs. blue team testing in cybersecurity

Red teaming is more than penetration testing

While penetration tests are a crucial aspect of security infrastructure testing and can include both manual tests and continuous automated penetration testing, red teaming goes much further. The red team simulates the actions of real-life threat actors, so penetration testing is only the beginning. Depending on the agreed scope of the exercise, the red team might use any techniques available to real attackers to perform simulated attacks, exploit security vulnerabilities, and obtain sensitive data. This means not only attacks against the IT infrastructure, network security, and application security but also attempts to bypass physical security. A red team’s attacks may last several weeks and include attempts at social engineering attacks such as identity fraud or phishing – a major cause of data breaches in organizations.

Assembling the red team

The simplest approach to red teaming is to designate an internal group of security professionals as the red team. While this may be the easiest option if you have the right skills in-house, you can often get better results when the red team members are external experts specializing in ethical hacking. This provides the most accurate assessment of your cybersecurity defenses, as internal staff might overlook some attack vectors or (intentionally or not) skip testing in areas they think are well secured. Dedicated red teams typically include ethical hackers, penetration testers, social engineering experts, and other security professionals with experience in circumventing various security measures.

Who are the blue team?

In a red team vs blue team exercise, the blue team are the defenders. If you have a dedicated security operations center (SOC), you can use your SOC staff as your blue team. Otherwise, your blue teamers could simply be the internal security team, though blue team members can also include staff other than security professionals. In a wider sense, security is everyone’s business, so trainings to build security awareness are a must all across the organization. While this is especially important for physical security staff, all employees need to know what to look out for and how to report unusual errors, suspicious behavior, or unexpected physical or electronic contacts.

What is a purple team?

Executing a full red team vs blue team simulation with a dedicated and independent red team can be costly and time-consuming. In some cases, organizations will instead run similar exercises with a purple team – an internal or external unit to act as both the red and blue teams. Its members will include security experts with diverse skill sets who can switch between being the red and blue teams. While not as effective as full-scale red vs. blue exercises, purple team operations can be useful to maintain security between more extensive tests or perform spot checks in large organizations.

Preparing for the attack

In a real-life attack, nobody will give you advance warning, so blue team preparation is less about bracing for impact and more about knowing how to use existing security controls, intrusion detection (IDS) and intrusion protection (IPS) systems, and incident response procedures. Detailed knowledge of the organization’s physical and virtual infrastructure is also vital.

As an example, you might already have some security solutions and procedures in place, and preparation could mean documenting and integrating them using a security information and event management solution (SIEM) to provide real-time threat intelligence. For websites and web applications, the blue team might run an online vulnerability scanner to find and then remediate weaknesses in web-based systems and infrastructures, including misconfigurations and forgotten test deployments.

For the red team, preparation is all about recon and research. If you hire external red teaming consultants, they might stake out and analyze your organization just like real attackers would. This may include scanning for vulnerabilities, mapping out the virtual and physical infrastructure, identifying security software and physical security systems, and harvesting staff identities and contact details for social engineering attacks. If physical access is needed, the red team might even resort to such tricks as setting up a dummy business to pose as a business partner or contractor.

Running the red team vs. blue team exercise

Unlike one-off events such as penetration tests, risk assessments, or security audits, a blue team vs. red team exercise tests the resilience of an organization doing its day-to-day business over a longer period. Depending on the agreed scope of operations, the red team can use this time to attempt all sorts of intrusions on all levels of the organization. In terms of cybersecurity, this might involve not just direct attacks against company websites, web applications, network infrastructure, and internal systems, but also social engineering tricks and phishing emails to obtain login credentials or install malware. Physical security can also be probed by trying to gain physical access to the client site and endpoints using fake or cloned employee IDs or simply posing as a delivery driver, cleaner, or builder.

The defending blue team has to stay alert and organized to detect and prevent infiltration attempts. To ensure that the exercise provides actionable results, detected attacks, exploited security vulnerabilities, and blue team responses should be carefully logged for postmortem analysis and remediation.

The benefits of red team vs. blue team tests

By simulating real-life attack scenarios, red team versus blue team exercises provide invaluable information about the condition of your organization’s security infrastructure. Combined with other ongoing security programs, such as security audits, physical security checks, and continuous web application vulnerability scanning, they can be an effective way to eliminate weak points and maintain a robust security posture in a constantly evolving threat environment.

Zbigniew Banach

About the Author

Zbigniew Banach - Technical Content Lead & Managing Editor

Cybersecurity writer and blog managing editor at Invicti Security. Drawing on years of experience with security, software development, content creation, journalism, and technical translation, he does his best to bring web application security and cybersecurity in general to a wider audience.