Freaks City

Binary Analysis with IDA Pro When analyzing check_in.exe, the following key observations were made: The program requires flag.jpg as input It performs XOR operations between file contents and a hardcoded key Output is written to hint.txt // Simplified decompiled code snippet void process_file() { FILE *input = fopen("flag.jpg", ...

In binary analysis, understanding data type representations is fundamental. Here are common data type definitions: _WORD (1 word = 2 bytes = 16 bits) _DWORD (2 words = 4 bytes = 32 bits) _QWORD (4 words = 8 bytes = 64 bits) _OWORD (8 words = 16 bytes = 128 bits) Assembly directives for data definition: DB (Define Byte): Defines single-byte ...

base64÷4: 1. Download the attachment, which is a .txt file. Open it to find a string of characters: 666C61677B45333342374644384133423834314341393639394544444241323442363041417D 2. Upon observation, the string consists of only numbers and uppercase letters. Considering the challenge name, it's likely base16 (hexadecimal) encoded. Decoding it yi ...

Overview This article covers fundamental exploitation techniques in binary security, focusing on practical examples from CTF challenges. The content assumes basic familiarity with assembly and memory layout concepts. Example 1: Command Execution via Input Filtering A Python script was provided that accepts user input and executes it using os.sy ...

Binary Analyssi First, examine the binary with IDA Pro. The main function performs the following operations: int main() { char input[24]; char encrypted_flag[] = "rxusoCqxw{yqK`{KZqag{r`i"; printf("please input flag"); scanf("%24s", input); if(strlen(input) != 24) { printf(&quo ...

Low Public Exponent Attack When the public exponent $e$ is sufficiently small relative to the modulus $n$, and the padded plaintext satisfies $m^e < n$, the modular reduction becomes ineffective. In this scenario, the ciphertext $c$ is effectively an integer $e$-th power. By iterating through potential multiples of $n$ added to $c$, one can ...

Information Gathering web1 Viewing page source code reveals the flag. Right-click context menu or Ctrl+U keyboard shortcut provides access. web2 Direct browser DevTools access may be restricted. Alternative approaches include: Prefixing URL with view-source: Using Ctrl+U keyboard shortcut Opening DevTools via Ctrl+Shift+I Intercepting network ...

PHP applications often implement multilpe layers of security filters that require creative bypass techniques. This analysis examines various PHP filter evasion methods including URL encoding, newline injection, and request priority manipulation. Initial Code Analysis The target application begins with source code inspection: <?php highlight_ ...

Direct use echo with backticks. First ls, then tac to read the flag. Challenge 2 The filter is quite restrictive. One effective method is the character increment bypass. A small script can enumerate which characters are allowed: for ($c = 32; $c < 127; $c++) { if (!preg_match("/[a-zA-Z0-9@#%^&*:{}\-<\?>\"|`~\\\\]/&q ...

The challenge presents a web application with login and registration functionality. The objective is to retrieve the hidden flag from the database. Initial Exploration Upon accessing the application, we notice registration and login options. Attempting to register with the username "admin" reveals that the account already exists, sugg ...