> For the complete documentation index, see [llms.txt](https://kf0k-blog.gitbook.io/ctf/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://kf0k-blog.gitbook.io/ctf/writups/sans/binary/bm01.md).

# BM01

## **About The Challenge** <a href="#about-the-challenge" id="about-the-challenge"></a>

| Type   | Difficulty |
| ------ | ---------- |
| Binary | Medium     |

## ‌Solution

The second binary challenge was also a Linux binary, but here it was not easy.&#x20;

![](https://3440279504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MM4TVxXO_3L3IYJHc1e%2F-MO7gwhvSc0D1oScWFOU%2F-MO7hIeMhql-KV1_8ojq%2FScreenshot_2020-11-13_17-15-46.png?alt=media\&token=574c6012-40fa-459b-86a9-6a2144da0817)

By executing the binary program, we prompting with the message *Can you get the flag out of me?.*&#x20;

In this challenge we have the debug the binary in order to solve it. We can use any debugger tools, I used IDA. &#x20;

![](https://3440279504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MM4TVxXO_3L3IYJHc1e%2F-MO7gwhvSc0D1oScWFOU%2F-MO7i4esLM2i8eOaXDvi%2FScreenshot_2020-11-13_17-17-09.png?alt=media\&token=873919cb-1c6e-40f1-8ed3-908f4563f0ba)

Using IDA I run the program to debug it. As previous figure shows on the left windows the functions that the program having, I make break point the end before the program stops and exit. To investigate the heap data and what is stored on the program memory.&#x20;

![](https://3440279504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MM4TVxXO_3L3IYJHc1e%2F-MO7gwhvSc0D1oScWFOU%2F-MO7ji-ijKs7az8iiQa3%2FScreenshot_2020-11-13_17-29-43.png?alt=media\&token=2f6fa326-3ea6-4a10-b027-6748bac34b79)

As above figure shows at the button section is heap data.&#x20;

![](https://3440279504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MM4TVxXO_3L3IYJHc1e%2F-MO7gwhvSc0D1oScWFOU%2F-MO7k9txV_lhLlLCiucO%2FScreenshot_2020-11-13_17-31-50.png?alt=media\&token=e2c9db0b-bc66-4634-a588-c6c5d5cc6f21)

I found the flag that is written in tiny letters.&#x20;

![](https://3440279504-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MM4TVxXO_3L3IYJHc1e%2F-MO7gwhvSc0D1oScWFOU%2F-MO7kbm4BEdRTLc4Mz0e%2FScreenshot_2020-11-13_17-33-15.png?alt=media\&token=50092ad0-b3c0-4013-92a8-ce82c8a2af4f)

After that, I used CyberChef in order to decode Hex values and get the actual letters.&#x20;

**Flag:** ⁿᵒᵗᴳᵒⁱⁿᵍᵀᵒᴹᴬᴷᴱᵗʰⁱˢᴼⁿᵉᔆ⁰ᴱᶻ