# CTF --- ## Hacking For Fun and Profit --- Capture the Flag (CTFs) are a special kind of information security competitions where the participants learn by solving innovative security challenges. --- ## FLAG ### CTFName{S0me_random_t3xt} --- # Types of CTFs --- ### Jeopardy Multiple challenges in a range of categories not limited to - web, cryptography, reverse engineering, binary exploitation, forensics, etc. You get points for solving challenges by submitting "flags", more the points higher you are on the scoreboard. --- ### Attack Defense Each participant has a VM/network that they defend/patch and attack others simultaneously --- # How to CTF? --- ### CTFtime * head over to https://ctftime.org/event/list/upcoming * Maintains a list of past and upcoming events with scores, challenges and writeups * Player submitted writeups --- # Categories to expect --- ### Web * Given - Website * Figure out the features and attack surfaces * Compromise and read the flag - file/db/env --- ### Web - Knowledge * Types of Vulnerabilities * XSS * SSRF * Logical - Login/logout * Deserialization * SSTI * SQLI * ... * Common vulnerability patterns and where to look for them --- ### Web - Tools * Burp Suite * python? * nmap? --- ### Reverse Engineering * Given - A program - binary(PE, ELF, Mach-O ..), js, bytecode etc * Figure out how it works - input/output * "reverse" the logic to get flag --- ### Binary Exploitation * Given * A program - binary(PE, ELF ..) * A remote ip/port where its running * Figure out how it works - input/output * Find out exploitable vulnerabilities * Get shell and/or read flag --- ### Reverse Engineering and Binary Exploitation - Knowledge * Assembly - x86/64, arm, mips ... * Executable File Format * OS internals * Process * Memory allocators * C/C++ and related vulnerability patterns --- ### Reverse Engineering and Binary Exploitation - Tools * Disassembler/Decompiler * radare2/cutter * ghidra * Hopper * Binary Ninja * IDA Pro --- ### Reverse Engineering and Binary Exploitation - Tools ... * Debuggers * windbg * gdb * lldb * Instrumentation * Pin * DynamoRIO * python? --- ### Crypto * Given * A program - binary(PE, ELF, python script) implementing a crypto system * A remote ip/port where its running * Find out weaknesses in the given crypto system/implementation * Use the weaknesses to "calculate" flag --- ### Crypto - Knowledge * Classical crypto systems - RSA, AES, DES, DH, ECC * Classical attack techniques * Known Implementation problems * Maths? --- ### Crypto - Tools * python? * sage --- ### Misc * Forensics * Steganography * Programming --- ### General Tools/Knowledge * Command Line Usage * IDEs - vim, VSCode, Sublime Text * Programming - python, golang ... --- ## Dos * Learn * Try new technologies * Talk with other teams and players * Be Active on the IRC/Slack/Telegram/Discord of the CTF --- ## Dont's * Use automated tools * Attack the infrastructure * Be Salty * Share Flags/Spoilers with other teams --- # Practice * https://www.root-me.org/ All categories * https://backdoor.sdslabs.co/ by IIT Roorkee's CTF team List at https://www.wechall.net/ --- # :muscle: :tada: --- ### Thank you! :sheep: You can find me on - [Twitter](https://twitter.com/_sudhackar) - or [email](mailto:sudhackar@outlook.com) me