NahmCTF 2024 writeups for Ring Cycle 3

Start We already known that program need us input correct passphrase, this time we get some other info: 1 2 3 4 ❯ ll valkyrie rhinegold basics -rwxr-xr-x 1 ada ada 16704 May 24 09:19 basics -rwxr-xr-x 1 ada ada 16768 May 24 09:19 rhinegold -rwxr-xr-x 1 ada ada 42584 May 24 09:19 valkyrie Here, the file size of this level is far greater than first two, maybe we guess there are more complex code(.

NahamCTF 2024 writeups for Ring Cycle 2

Start Like the first one, the program also need us to input the correct passphrase to get the flag. 1 2 3 4 ❯ ./rhinegold What is the passphrase of the vault? > hello world Wrong passphrase! Code Content Load it into IDA, we could quickly get of this, which almost as the first one in main function: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 printf("What is the passphrase of the vault?

NahamCTF 2024 writeups for Ring Cycle

Basic Getting Started I had just solved the first three challenges in these series. These all have the similar pattern, which requires you enter a correct passphrase, then the flag will print to stdout, Otherwise, print error info and exit. 1 2 3 4 ❯ ./basics What is the passphrase of the vault? > give me the flag Wrong passphrase! Basic Analysis the program will check our passphrase, so there must be some operations with the input passphrase.

Rust Hacking - Compound Type (Part II)

这次我们来看看在 Rust 中如何表示 Compound Type (内存中),新建示例项目,并打开 src/main.rs 写入如下代码: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Rust Hacking - Scalar Type (Part 1)

最近遇到很多 Rust 的二进制程序,在分析中遇到了比较多的问题,所以本系列打算从基础开始,总结一些分析 Rust 二进制的基本步骤以及相关的技巧。 Scalar Type 首先我们

Flare2-challenge-04

文件信息 解压之后使用 DIE 查看文件信息: 可以看到有明显的 UPX 特征码,首先尝试使用其自带的脱壳功能: 程序分析 脱壳之后即是正常的 PE 程序,在虚拟机中运行

Flare2-challenge-03

文件信息 解压密码 flare, 解压之后得到 elfie.exe, 同样,使用 DIE 查看文件信息: 且文件有一个“特殊”图标(pyinstaller) strings 命令可以看到 pyinstaller 相关的特征字符串

Flare2-challenge-02

文件信息 使用 flare 密码解压之后得到 very_success.exe 文件,DIE 查看 PE 信息: 代码分析 安全环境中(虚拟机)执行此程序,可以看到提示输入 key: 且初步判断与命令行参数、程

Flare2-challenge-01

文件信息 下载 flare_on_start_2015 后,首先使用DIE 查看文件信息: 检测到该文件是cabinet_format 格式(一种压缩格式,运行时自解压)。运行之后会提示同