What is a CTF?

Capture The Flag is a special kind of Cybersecurity competition designed to challenge and educate participants through a series of real-world scenarios and problems. It’s a fantastic opportunity for both beginners and experienced participants to hone their skills, learn new techniques, and see how they stack up against their peers.

Capture The Flag (CTF) competitions offer a variety of engaging formats, each with its own unique challenges and learning opportunities. Some of the well-known formats include Jeopardy-style, Attack-Defense, King of the Hill, and mixed-style CTFs, among others. Jeopardy-style CTFs present participants with a range of individual challenges to solve, while Attack-Defense competitions simulate real-world scenarios where teams are required to attack their competitors’ systems while defending their own. King of the Hill contests have participants vie for control over a single server, and mixed-style CTFs combine elements from various formats to offer a diverse set of challenges. Regardless of the format, these events are designed to test various cybersecurity skills, encouraging participants to think critically, work collaboratively, and constantly learn.

CTF Type	Description
Cloud Security CTF	Given the rise of cloud computing, some CTFs might focus on this aspect. This can include tasks related to cloud misconfigurations, cloud-native technologies, API security, and more.
King of the Hill	In these CTFs, participants compete to maintain control of a particular server or service by patching its vulnerabilities and exploiting those in others’ systems. The longer a team holds the “hill”, the more points they gain. There’s a single (or set of) machine(s) or network that all teams compete over. The objective is to first exploit the target system, then once gaining control, set up defenses to maintain control against other teams’ attacks. The team that manages to maintain control of the system for the longest time period (remains the “King of the Hill”) is the winner.
Attack-defense style	In these CTFs, each team is given a server (or set of servers) to defend while simultaneously attempting to attack the other teams’ servers. The goal is to exploit vulnerabilities in the opponents’ infrastructure to capture their flags, while patching the vulnerabilities in your own system to prevent them from doing the same. These types of competitions often mirror real-world cybersecurity scenarios and can be very intense.
Jeopardy-style	In this type of CTF, teams or individuals solve problems in a range of categories (such as Web, Forensics, Cryptography, Binary, Reverse Engineering, and others). Each problem solved yields a flag, which can be submitted for points. The problems are typically ordered by difficulty, with harder problems worth more points.
Red Teaming CTF	While most CTFs involve individual challenges or puzzles, a Red Teaming CTF involves a full simulated attack against a network or system, similar to a real-world penetration testing scenario.
Lockpicking/Physical Security CTF	While not directly related to cyber, these challenges test physical security skills like lockpicking, bypassing access controls, etc. It’s a fun and engaging way to remind participants that not all security is digital.
Web Application Security CTF	These events specifically focus on the security of web applications. They might involve exploiting web app vulnerabilities, SQL injection, Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and more.
Cryptanalysis CTF	These events focus specifically on cryptography and may involve challenges related to breaking ciphers, understanding cryptographic protocols, or exploiting weaknesses in cryptographic implementations.
Boot2root / Penetration Testing	These CTFs involve downloading a vulnerable virtual machine, and the objective is to exploit its vulnerabilities to gain root access, hence the name “Boot2root”.
Threat Hunting CTF	Participants access a simulated network and proactively seek signs of malicious activity.
Forensics CTF	Focuses on digital forensics skills, including analyzing disk images, memory dumps, network traffic, and more.
Incident Response CTF	Focuses on responding to cybersecurity incidents. Scenarios, logs, network captures, or system images are provided for analysis and remediation proposal.
Blue Team CTF	Emphasizes defensive security skills like system hardening, alert response, and managing security infrastructure.
Digital Forensics CTF	These challenges focus specifically on the skills used in digital forensics investigations, such as data recovery, steganography, log analysis, and incident response.
Secure Coding CTF	Challenges involve identifying security flaws in code, fixing flaws, or writing new code to meet certain security requirements.
OSINT CTF	Open Source Intelligence (OSINT) challenges test the participants’ ability to gather information that is publicly available but may not be immediately apparent. This can involve searching through public databases, social media, websites, and other digital traces.
Social Engineering CTF	While this might be less common (and more controversial due to ethical reasons), some competitions might include tasks related to social engineering. This can involve aspects such as phishing, physical security tests, or other types of human manipulation techniques.
Car Hacking CTF	With vehicles becoming more and more computerized, car hacking has become a field of interest for both researchers and attackers. Car hacking CTFs can involve challenges related to vehicle systems, including infotainment, vehicle network protocols like CAN bus, and even autonomous driving systems.
Container Security CTF	As more and more organizations move to containerized applications using technologies like Docker and Kubernetes, understanding the security implications of these technologies is crucial. These CTFs focus on container-specific vulnerabilities and defenses.
Blockchain/Cryptocurrency CTF	With the rise of decentralized finance and blockchain technology, this type of CTF has emerged recently. It focuses on the security of blockchain technology, smart contracts, and cryptocurrencies.
IoT Security CTF	With the rise of Internet of Things (IoT) devices in our everyday life, IoT Security CTFs are becoming more common. These can involve tasks like analyzing and exploiting vulnerabilities in IoT devices.
ICS/SCADA CTF	Industrial Control Systems (ICS) and Supervisory Control and Data Acquisition (SCADA) systems are critical infrastructure often targeted by attackers. CTFs in this area involve understanding these systems, finding vulnerabilities, and learning about defending such systems.
Wireless Security CTF	These challenges deal with vulnerabilities and exploits specific to wireless networks and protocols, such as WiFi, Bluetooth, and cellular networks.
Machine Learning / AI Security CTF	While not directly related to cyber, these challenges test physical security skills like lockpicking, bypassing access controls, etc. It’s a fun and engaging way to remind participants that not all security is digital.
Mobile Device Security CTF	These competitions focus on vulnerabilities and security issues related to mobile devices and applications. Tasks may involve both Android and iOS platforms, and might include aspects such as reverse engineering, app vulnerability exploitation, or mobile forensics.
Hardware CTF	These competitions focus on the hardware aspect of cybersecurity. This might involve tasks related to embedded systems, IoT devices, or reverse engineering of hardware components.

Posted by Eskista Hacker