What Is Red Teaming? Methodology, Tools, and Benefits

Most organizations test their security by scanning for known vulnerabilities and calling it a day. Red teaming takes a different approach: it assumes an attacker is already motivated to break in, and asks the question—can they?

The answer is almost always yes. According to the SANS Institute's 2025 Offensive Security Survey, over 80% of red team engagements achieve their primary objective, whether that's accessing sensitive data, compromising a domain controller, or reaching a critical system. The finding isn't surprising. Red teams don't just look for holes in firewalls—they test the entire chain of people, processes, and technology.

TL;DR

What it is: Red teaming is a controlled adversarial exercise where security professionals simulate real-world attacks to test an organization's defenses
Why it matters: It exposes blind spots that vulnerability scans and standard penetration testing miss—especially gaps in human behavior and incident response
Key takeaway: Organizations with mature security postures should run red team exercises at least annually to validate their detection and response capabilities

What Is Red Teaming?

Red teaming is a security assessment where authorized professionals emulate real adversaries' tactics, techniques, and procedures to test an organization's ability to prevent, detect, and respond to attacks. NIST defines a red team as "a group of people authorized and organized to emulate a potential adversary's attack or exploitation capabilities against an enterprise's security posture." Unlike narrow vulnerability scans, red teaming evaluates the full spectrum of defenses—from technical controls and physical security to employee awareness and incident response processes.

How Does Red Teaming Work?

A red team engagement follows a structured methodology that mirrors how real attackers operate. The typical engagement runs anywhere from three weeks to several months, depending on scope and objectives.

Phase 1: Planning and Scoping

The engagement starts with defining rules of engagement, objectives, and boundaries. The red team and the client agree on what's in scope (specific networks, applications, physical locations), what's off-limits, and what success looks like. A common objective might be "exfiltrate customer PII from the production database" or "gain domain admin access without triggering an alert."

Phase 2: Reconnaissance

Red teamers gather intelligence using open-source intelligence (OSINT) techniques—scanning public records, LinkedIn profiles, leaked credentials from previous breaches, DNS records, and exposed services. This mirrors exactly how real threat actors prepare for targeted attacks. If you've followed our coverage of groups like APT28 targeting European organizations, you'll recognize the pattern: attackers spend weeks or months on recon before sending a single packet.

Phase 3: Initial Access

Armed with intelligence, the team attempts to gain a foothold. Methods include phishing emails crafted using information gathered during recon, exploiting public-facing vulnerabilities, credential stuffing with leaked passwords, or even physical intrusion (tailgating into a building, dropping USB drives in parking lots).

Phase 4: Persistence and Lateral Movement

Once inside, the team establishes persistence—creating backdoors, stealing credentials, and moving laterally through the network. They escalate privileges, hop between systems, and work toward the agreed-upon objective. This phase tests whether your detection tools actually catch attacker behavior in a production environment, or whether your security team only notices after the damage is done.

Phase 5: Objective Completion and Reporting

After achieving (or failing to achieve) the objective, the red team documents everything: the attack path, which controls failed, which succeeded, and what the blue team detected versus what they missed. The final report includes specific remediation steps prioritized by risk.

Red Teaming vs. Penetration Testing

These terms get used interchangeably, but they're different exercises with different goals.

Penetration testing is scoped, time-boxed, and focused on finding as many vulnerabilities as possible in specific systems. The security team usually knows testing is happening. A typical pentest runs two to six weeks and delivers a list of findings ranked by severity.

Red teaming focuses on a specific objective and tests whether an attacker can achieve it end-to-end. The blue team (defenders) typically doesn't know testing is in progress. Red teams use stealth, patience, and creativity—they might chain together a phishing attack, a privilege escalation bug, and a misconfigured cloud service to reach their goal. The exercise tests detection and response capabilities, not just vulnerability counts.

Think of it this way: a pentest tells you where the holes are. A red team tells you whether someone can actually walk through them while your security team watches.

Organizations earlier in their security maturity should start with penetration testing. Red teaming makes the most sense when you already have a security operations center, incident response procedures, and layered defenses that you want to validate under realistic conditions.

What Tools Do Red Teams Use?

Red teams use a mix of commercial and open-source tools that mirror what real attackers deploy. Here are the categories that matter most:

Command and Control (C2) frameworks — Cobalt Strike remains the industry standard for managing implants and post-exploitation. Open-source alternatives like Mythic and Sliver have grown significantly. Interestingly, these same frameworks show up in real attacks—we've seen threat actors repurposing legitimate red team tools in live campaigns.

Reconnaissance tools — Shodan, Censys, and SpiderFoot for external attack surface mapping. theHarvester and Maltego for OSINT gathering.

Exploitation frameworks — Metasploit for vulnerability exploitation, Impacket for Windows protocol attacks, and BloodHound for Active Directory attack path analysis.

Social engineering — Gophish for phishing campaigns, Evilginx for adversary-in-the-middle attacks, and the Social Engineering Toolkit (SET).

Post-exploitation — Mimikatz for credential extraction, Rubeus for Kerberos attacks, and CrackMapExec for lateral movement.

Red Teaming Frameworks and Standards

Several formal frameworks guide how red team engagements are planned and executed:

TIBER-EU — The Threat Intelligence-Based Ethical Red Teaming framework, developed by the European Central Bank. It's mandatory for certain financial institutions in the EU and requires threat intelligence providers to develop custom attack scenarios based on real threat actors relevant to the target.

CBEST — Published by the Bank of England, CBEST applies a similar threat intelligence-driven approach specifically to UK financial institutions.

PTES (Penetration Testing Execution Standard) — A broader standard covering all offensive security engagements, including red teaming. It defines seven phases from pre-engagement through reporting.

MITRE ATT&CK — While not a red teaming standard per se, the ATT&CK framework maps adversary tactics and techniques that red teams use to structure their attacks and report findings in a common language.

What About AI Red Teaming?

AI red teaming has emerged as its own discipline. CISA defines it as a method of testing AI systems by simulating attacks or misuse scenarios before real attackers can exploit them. This includes prompt injection attacks, data poisoning, model extraction, and testing for harmful outputs.

It's a fast-growing field. As organizations deploy AI agents with real-world access—managing infrastructure, processing financial transactions, handling customer data—the attack surface expands in ways that traditional red teaming wasn't designed to cover. NIST has published a separate glossary entry for AI red teaming, recognizing it as a distinct practice from conventional security testing.

How to Build a Red Team Program

If you're considering red teaming for your organization, here's a practical path:

Assess your maturity first. If you don't have basic vulnerability management, endpoint detection, or incident response plans in place, start there. Red teaming against immature defenses produces predictable results and limited value.
Define clear objectives. "Test our security" is too vague. Good objectives tie to specific business risks: "Can an attacker reach our payment processing system from the internet?" or "Can a compromised employee laptop lead to customer data exfiltration?"
Choose the right provider. Look for teams with relevant certifications (OSCP, OSCE, CRTO) and experience in your industry. Ask for sample reports and references.
Involve leadership. Red team results often expose uncomfortable gaps. Executive buy-in ensures findings actually lead to budget and prioritization changes, not just another report gathering dust.
Follow up with purple teaming. After the red team engagement, run collaborative exercises where the red and blue teams work together to replay attacks and improve detection rules. This is where the real defensive value comes from.

For more on building strong security foundations, check out our security guides and our coverage of access control best practices—getting identity and permissions right is often the first line of defense red teams try to breach.

Frequently Asked Questions

How much does a red team engagement cost? Costs vary widely based on scope, duration, and provider. A basic engagement targeting a specific objective might run $20,000–$50,000 over two to three weeks. Large-scale engagements with physical intrusion, social engineering, and extended timelines can exceed $150,000. The price reflects the expertise required—red teamers are among the highest-paid professionals in cybersecurity.

How often should organizations run red team exercises? Most security frameworks recommend annual red team assessments at minimum. Organizations in highly regulated industries (finance, healthcare, critical infrastructure) or those facing active threat groups may run them semi-annually. Between formal engagements, continuous automated red teaming (CART) tools can provide ongoing validation.

What's the difference between a red team and a purple team? A red team operates independently, simulating attacks without the defenders' knowledge. A purple team is a collaborative exercise where red and blue teams work together in real time—the red team executes attack techniques while the blue team tunes detections and response procedures. Purple teaming is often more cost-effective for improving specific defensive capabilities.