What Does the Blue Team Do in Cybersecurity? | Red vs Blue Explained

When I first learnt about cybersecurity, I kept seeing people say they were “on the blue team” and I had no idea what the hell that meant.

Here’s the quick breakdown 👇

In cybersecurity, there are two broad sides, both with different responsibilities;

🔴 Red team = The Attackers

They simulate legal hackers, their job being to break in, find flaws and show you what needs fixing, improving security.

🔵 Blue teams = The Defenders

Using a tool called a SIEM (Security Information and Event Management) they watch systems, catch attackers, write detection rules and are responsible for reacting to attacks. Think of them as digital security guards + forensic analysts.

Technically, other teams can exist but these will be looked into at another date.

🛡️What do blue teams actually do?

Their main roles consist of reading logs, writing detection rules (often using python), setting alerts, analysing malware behaviour, cleaning up incidents to make sure the companies systems aren’t at risk and are the unseen layer of defence that keep companies running, especially with sensitive data (like banks, hospitals and most government systems with valuable data)

📊What is worth protecting?

Data. Plain and simple, in most cases, data can be categorised into two categories: PII and SPII

PII (Personally Identifiable Information): Basic data that can identify a person, name, email, phone number, address, date of birth.

SPII (Sensitive Personally Identifiable Information): A stricter category that includes highly sensitive data, think passport numbers, Social Security numbers, biometric data, medical records, financial account info, etc.

SPII is crucial in protecting; SPII leaks are what get companies sued and people fired.

❓Why learn blue team cybersecurity?

Simple, they’re often overlooked but blue teams are the one line of defence main between a company and their data being leaked, cases like the 2013 Yahoo data breach with over 3 billion exposed user accounts cement the need for blue teams; defence pays, companies will pay to prevent data leaks due to insane fines.

As technology evolves, so do attacks; AI-assisted hacks, deepfake social engineering, defenders need to evolve faster. No-one knows what cybersecurity will look like in 10 years, staying sharp isn’t a choice but a requirement in this field.

Thanks for reading, next week we’ll be looking into the CIA triad.