Cybersecurity red teams vs. blue teams: Differences and similarities
Cyberthreats constantly evolve. By combining offensive and defensive teams, organizations can strengthen their defenses.
By: Genevieve Carlton, Edited by: Mitch Jacobson
Published: September 9, 2025
Technology is part of everyday life, and, unfortunately, so are cyberattacks. How can organizations defend against these attacks? Cybersecurity red teams and blue teams are a valuable tool.
What's the difference between red teams vs. blue teams? Red teams focus on offense, simulating cyberattacks. Blue teams focus on defense, safeguarding networks and systems. Together, they prevent harmful cyberattacks and data breaches.
What is a red team?
A red team is an offensive IT unit that simulates cybersecurity attacks to help organizations strengthen their systems and procedures. These ethical hackers break into secure networks, extract data, and disrupt operations. By mimicking cyberattacks, red teams provide valuable insights into how cybersecurity teams can prevent real-world attacks.
How does a red team test security systems? By attacking their weakest points. In response, the blue team attempts to stop the red team's attacks and protect sensitive data and private networks.
By staging a simulated cybersecurity attack, the red team identifies areas of weakness and helps the blue team strengthen defensive techniques.
Red team strategies and skills
The strategies used by red teams mirror real-world cyberattack techniques. They may employ phishing, malware, and physical attacks to uncover unguarded entry points.
Specific red team tactics depend on the target. Data extraction attacks often target AI and machine learning systems, while phishing emails can break through firewalls.
Members of the red team need exceptional hacking skills. To successfully test networks, red team specialists also use their knowledge of cyberattack strategies.
Red team strategies
- Social engineering, such as phishing emails
- Physical attacks that target hardware and infrastructure
- Data extraction attacks that copy data without altering it
- Advanced Persistent Threats (APTs) to gain long-term access to systems
Red team skills
- Penetration testing
- Adversary emulation
- Threat intelligence
After simulating an attack, the red team creates a report identifying vulnerabilities and suggesting changes.
Red team operations can target physical infrastructure, third-party vendors, and the organization's employees. (Human error is a major factor in many successful security breaches.)
The limits of red teaming
As an offensive unit, red teams only succeed if used proactively. They cannot respond to an attack after it has taken place. Instead, organizations must deploy red teams before attacks to improve security operations.
Successful red team attacks mimic real cyberattacks. This gives blue teams valuable information about how to respond in an operational environment.
What is a blue team?
While the red team attacks to test cybersecurity systems, the blue team defends. The blue team monitors systems for unauthorized intrusions, responds to security incidents, and investigates attacks using digital forensics tools. They also implement mitigation techniques to strengthen security.
Blue teams receive no warning from the red team before an attack. As a result, they don't know whether an attack is real or simulated. This is the best way to test the cybersecurity team's defensive strengths.
A red team attack can happen at any time. Therefore, blue teams must maintain constant vigilance to effectively defend their organization.
Blue team strategies and skills
The blue team uses the same strategies to defend against red team attacks and real-world cyberattacks. As a result, the simulated red team attacks can help blue teams strengthen their monitoring and response abilities.
Successful blue teams employ some of the same skills that red teams rely on. Both must stay current on the latest cyberthreats. However, the blue team uses its skills to defend rather than attack.
Blue team strategies
- Security monitoring to detect cyberattacks in real time
- Incident response when security monitoring tools identify a threat
- Managing network and system security infrastructure
- Security analysis to investigate incidents
Blue team skills
- Threat intelligence
- Digital forensics
- Security infrastructure
Does the blue team know when the red team will attack? Maintaining the element of surprise is the best way to replicate real-world conditions.
When red team operations conclude, blue teams modify their security systems and approaches to prevent future attacks.
Hackers can exploit countless cybersecurity vulnerabilities. That means blue teams need diverse defensive skills and a strong understanding of monitoring and detection systems.
The limits of blue teaming
Blue team operations strengthen the detection and incident response skills that cybersecurity teams need. However, the pressure of constantly monitoring for simulated and real attacks can be stressful.
In addition, blue teams must continually upskill to stay ahead of threats. By working together with red teams, blue teams can strengthen an organization's cyber defenses.
Snapshot of red teams vs. blue teams
| Aspect | Cybersecurity red teams | Cybersecurity blue teams |
|---|---|---|
| Primary Function | Simulate attacks | Respond to attacks |
| Goal | Aim to strengthen security procedures and infrastructure by identifying weaknesses | Aim to strengthen monitoring, detection, and incident response skills |
| Strategies | Employ strategies including social engineering and penetration testing | Employ strategies including intrusion detection and incident response |
| Skills | Rely on ethical hacking and penetration testing skills | Rely on security infrastructure and digital forensics skills |
| Job titles | Include job titles, such as red team engineer, penetration tester, and adversary emulation specialist | Include job titles, such as incident responder, digital forensics analyst, and threat analyst |
| Certifications | May pursue certifications like certified ethical hacker and certified penetration testing professional | May pursue common certifications like certified information systems security professional and CompTIA Security+ |
| Responsibilities | Are responsible for reporting on security weaknesses and vulnerabilities | Are responsible for implementing new tactics and tools to prevent attacks |
How red teams and blue teams work together
Pairing offensive and defensive strategies gives organizations valuable insights into their vulnerabilities. When red teams and blue teams work together, they can prepare for evolving threats.
Staying ahead of cyberthreats poses a challenge for both red teams and blue teams. Threats continually evolve, making it difficult to simulate or defend against sophisticated attacks. However, a coordinated effort between red teams and blue teams helps organizations create the strongest possible defenses.
What about purple teams? A purple team brings together red team and blue team members to collaborate on threat detection, incident response, and adaptive defenses. The purple team provides continuous feedback to cyber defense operations.