0x00 Challenge Info After struggling to secure our secret strings for a long time, we finally figured out the solution to our problem: Make decompilation harder. It should now be impossible to figure out how our programs work! 0x01 Reconnaissance First we can run the binary to see what’s going on. ┌──(kali㉿kali)-[~/CTF/rev_behindthescenes] └─$ ./behindthescenes ./challenge <password> It tell us we should put some password as the argument to execute this. Next step, I check the printable str ...

0x00 Challenge Info We’ve located the adversary’s location and must now secure access to their Optical Network Terminal to disable their internet connection. Fortunately, we’ve obtained a copy of the device’s firmware, which is suspected to contain hardcoded credentials. Can you extract the password from it? 0x01 Reconnaissance It gave us a zip file. So we first unzip it with the password hackthebox. Then we can see a directory called ONT which stands for Optical Network Terminal. The interest ...

Prologue All the following example will be shown in C Programming Language or pseudo code. This is the note when I was taking the course in NCKU, 2024. Blablabla… Finally, I would like to declare that almost every photo I use comes from the handouts of my course at NCKU, provided by the professor. If any photo comes from another source, I will give proper credit in the caption or description of the image. Complexity Space Complexity The amount of memory that it needs to run to completion. S(P)= ...

0x00 Challenge Info Qubit Enterprises is a new company touting it’s propriety method of qubit stabilization. They expect to be able to build a quantum computer that can factor a RSA-1024 number in the next 10 years. As a promotion they are giving out “time capsules” which contain a message for the future encrypted by 1024 bit RSA. They might be great engineers, but they certainly aren’t cryptographers, can you find a way to read the message without having to wait for their futuristic machine? ...

Prologue Chinese Remainder Theorem (CRT) is also known as Sun zi’s Theorem. It first appear on the Chinese book called Sūnzǐ Suànjīng, literally The Mathematical Classic of Master Sun/Master Sun’s Mathematical Manual. Here’s the math question in that book. 今有物不知其數，三三數之餘二，五五數之餘三，七七數之餘二，問物幾何？ There is something, but we do not know its exact quantity. When divided by 3, the remainder is 2; when divided by 5, the remainder is 3; when divided by 7, the remainder is 2. What is the quantity? To solve ...

Prologue This article is mainly intended to serve as my own cheat sheet and notes, but if it can also help you, that would be great. The content is summarized from the original document, so you can regard this article as an TL;DR version of the document per se. I will consistently update the content if I find something missing or something worth to be noted. You can also contact me to update the content. Types of SQL Injection There’re 5 types of SQLi vulnerability or 5 ways that SQLMap can test ...

0x00 Challenge Info You are after an organised crime group which is responsible for the illegal weapon market in your country. As a secret agent, you have infiltrated the group enough to be included in meetings with clients. During the last negotiation, you found one of the confidential messages for the customer. It contains crucial information about the delivery. Do you think you can decrypt it? This is the description of the challenge, let’s see the encrypting script and try to decrypt it! 0 ...