Red team, blue team and purple team - the differences

A red team is a group of specialists who simulate the behaviour of a real attacker in order to uncover weaknesses before a criminal exploits them. A blue team is the defensive side, the people and technology who detect, stop and investigate attacks. A purple team is not a separate team but a way of working in which the red and blue teams collaborate and exchange findings in real time so that defences improve faster.

These terms come from military terminology, where "red" represents the enemy and "blue" represents your own forces. In cyber security they describe three complementary roles that together make up a mature security programme. Below we explain each role concretely, compare them, and clarify how companies and businesses in Mostar, BiH and the wider region can choose an approach that genuinely benefits them.

What a red team is and what it does

A red team does what a real attacker would do, but under controlled and pre-agreed conditions. The goal is not merely to find a vulnerability, but to prove what an attacker can achieve with it: reaching a database, an administrator account or business-critical systems. For that reason a red team most often focuses on a "scenario" (for example, "reach the customer data") rather than simply enumerating vulnerabilities.

A typical red team engagement combines several techniques:

• Reconnaissance - gathering publicly available information about the target: domains, e-mail addresses, technologies, employees.
• Initial access - phishing, exploiting a vulnerable application or a weak password to get into the network.
• Lateral movement - spreading through the network from one compromised machine towards more valuable systems.
• Privilege escalation - obtaining higher permissions, ideally administrator-level.
• Reaching the objective and reporting - demonstrating impact and providing a detailed description of how the attack was carried out.

It is important to distinguish a red team from a classic penetration test. A penetration test is usually narrower and more technical. It tests a specific application, network or system within a defined scope and aims to find as many vulnerabilities as possible. A red team is broader and goal-oriented: it often includes social engineering, physical access and a longer duration, and as a rule the defensive team does not know in advance when the attack will begin. For most small and medium-sized companies a penetration test is the right first step, while a full red team is more appropriate for organisations that already have established defences and want to put them to a realistic test.

What a blue team is and how it defends

The blue team is the defensive side. These are the people and processes that protect the organisation every day: they monitor events, detect suspicious behaviour, respond to incidents and harden systems. While a red team can be an external team engaged for a few weeks, the blue team is most often a permanent function, an internal department or an external partner in the form of a managed security service.

Main activities of a blue team

• Monitoring and detection - watching logs, network traffic and endpoint behaviour, most often with the help of SIEM and EDR tools.
• Incident response - stopping an attack in progress, isolating infected devices and recovering systems.
• Hardening - closing unnecessary services, patching vulnerabilities and applying secure configurations.
• Vulnerability management - regular scanning, prioritisation and remediation of weaknesses before someone exploits them.
• Threat intelligence - tracking current threats and adapting defences to new attacker tactics.

A good blue team does not measure success by the fact that "nothing happened", but by how quickly it detects and stops an attack. Two key metrics are time to detection and time to response: the shorter they are, the smaller the damage. It is precisely these numbers that the red team and purple team approaches help reveal the true state of.

What a purple team is

The name purple team comes from mixing the colours red and blue. The idea is simple: instead of attackers and defenders working separately and only exchanging a report at the end, they collaborate during the testing itself. The red team performs a particular technique, and the blue team immediately checks whether their defences even registered it. If not, together they uncover why and what needs adjusting.

A purple team is most often not a permanent team but a way of working. In practice it looks like this:

1. The red team selects a specific attack technique, for example a particular way of stealing credentials.
2. The technique is performed in a controlled environment, with the blue team's knowledge.
3. The blue team checks whether their tools raised an alert and whether the detection was accurate.
4. If detection was missing, the rules, alarms or configurations are adjusted together.
5. The test is repeated until the defence reliably recognises the attack.

The advantage of this approach is the speed of learning. A classic red team provides a valuable picture of the situation, but the feedback only arrives in the final report. A purple team turns every test into an opportunity for immediate improvement of the defences, which is especially useful for companies building their security capabilities from scratch.

MITRE ATT&CK as a common language

For the red and blue teams to be able to communicate about the same things at all, they use a shared framework. The most widespread is MITRE ATT&CK, a publicly available knowledge base that lists the tactics and techniques attackers actually use, from initial access to data exfiltration. Each technique has its own code and description, so the red team can state precisely which technique it performed, and the blue team can check whether their detection covers it.

In practice, so-called coverage mapping is often done: on the matrix of techniques, you mark which attacks the defence reliably detects, which it detects partially, and which it does not detect at all. This way, instead of a subjective impression of security, you get a concrete map of gaps. For companies in the region that are only just building their security programme, this framework is useful because it turns the abstract question "are we secure" into a list of verifiable items that can be worked on systematically.

Comparison: red, blue and purple team

Characteristic	Red team	Blue team	Purple team
Role	Attack and threat simulation	Defence and detection	Collaboration and knowledge exchange
Goal	Prove the real impact of an attack	Detect and stop an attack	Accelerate improvement of the defence
Duration	Occasional, project-based	Continuous	As needed, through workshops
Who knows about the test	Most often only a small circle	Permanently operational	Both sides collaborate openly
Main outcome	Attack scenario and report	Faster detection and response	Concretely tuned detection rules

It is important to understand that these three approaches are not competitors but complement one another. A red team without a blue team produces a list of problems that no one defends against; a blue team without a red team defends against imagined rather than real attacks; a purple team connects the two so that the whole organisation progresses faster.

Which approach to choose for a company in BiH and the region

The choice depends on the maturity of your security, the size of the organisation and the budget. For most small and medium-sized businesses in Mostar and the wider region, the recommended order looks roughly like this:

• If you are just starting out: begin with a penetration test and basic vulnerability management. First you need to close the obvious holes.
• If you already have basic defences: introduce continuous monitoring and detection, either with an internal blue team or through an external managed service.
• If you have an established SOC or MDR: consider a red team engagement to realistically check how well your defence actually works.
• If you want to raise your level quickly: purple team workshops give the fastest feedback because they immediately turn findings into improvements.

In practice, many companies do not have the resources for their own team monitoring security around the clock. This is where the managed detection and response (MDR) model helps, with an external partner taking on the role of the blue team. Through its service Guardian 360 SOC and other services, NeoBit covers both the defensive and the offensive side, from penetration testing to continuous monitoring and incident response.

If you are not sure where your organisation stands, a good starting point is a brief scope assessment. By completing the penetration testing questionnaire you get a clearer picture of what you realistically need, and our team can propose a suitable approach without unnecessary cost.

How these three teams work together in practice

The most mature security programmes do not pick just one approach but combine them cyclically. The red team uncovers a realistic attack path, the blue team strengthens detection based on that, and purple team workshops ensure that what was learned is actually built into tools and processes. After several cycles, the organisation gains not only patched vulnerabilities but a measurably better ability to recognise and stop an attack.

For companies in BiH that do business with clients in the EU or are preparing for ISO 27001, this approach has added value: it documents that security is not a one-off piece of paper but a process that is regularly tested and improved. If you would like to discuss what the next step is for your organisation, get in touch and we will arrange an assessment.

Common misconceptions about these terms

Several misunderstandings circulate around these terms, and they can cost companies dearly if not corrected in time:

• "A red team is just a more expensive penetration test." It is not. The difference is in the goal: a red team measures how well the defence responds to a realistic attack, not how many vulnerabilities exist. If you do not have a defence that would respond, you are wasting a red team.
• "We have antivirus and a firewall, so we have a blue team." Tools are not a team. A blue team is the people and processes that monitor those tools, interpret alerts and respond. A tool on its own, without someone watching its output, rarely stops a serious attack.
• "A purple team means we need a third team." No. It is collaboration between existing people, not new hiring. Even when the red and blue teams are external partners, they can work in the purple model.
• "One test solves the problem." Security is a moving target. New vulnerabilities and new tactics appear constantly. A test shows the state at the moment of testing, so it makes sense to repeat it periodically.

Correcting these misconceptions is usually the first step towards a realistic plan. When it is clear what each approach actually does, it is easier to allocate a limited budget where it brings the greatest benefit.

Frequently asked questions

Is a red team the same as a penetration test?

No, although they overlap. A penetration test is narrower and more technical, focused on finding as many vulnerabilities as possible within a defined scope. A red team is broader and goal-oriented: it simulates a real attack scenario, often includes social engineering and lasts longer, and the defensive team usually does not know in advance when the attack begins.

Does a small company need a red team?

Most small companies first need a penetration test and basic security monitoring, not a full red team. A red team makes the most sense when an organisation already has established defences and wants to test them realistically. Without existing detection, a red team will only confirm what is already assumed.

Is a purple team a separate team that needs to be hired?

Most often not. A purple team is a way of working in which the existing red and blue teams collaborate during testing, not a separate department. It can be organised through occasional workshops in which attackers and defenders jointly check and tune detection.

Can an external partner take on the role of the blue team?

Yes. Many companies do not have the resources for their own team continuously monitoring security, so they use the managed detection and response (MDR) model, where an external partner takes on monitoring, detection and incident response. This provides access to an experienced blue team without building an entire department in-house.

Related guides: Cyber security in BiH - the complete guide · Black box, white box and grey box testing - the differences · Penetration testing vs vulnerability scanning - what to choose