> For the complete documentation index, see [llms.txt](https://ad3n.gitbook.io/ad3n/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ad3n.gitbook.io/ad3n/home/ctf-writeups/htb-university-ctf-2023/reverse-engineering.md).

# Reverse Engineering

* ## BioBundle

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2Fe2zlITZl4AEFsWKQ6YkR%2FBio%20bundle.jpg?alt=media&amp;token=c83b313a-6431-4605-843b-e0cce34722be" alt="" width="407"><figcaption></figcaption></figure>

### Unintended solution(?):

When execute the binary file, does not output anything unless try to give it some which result in `[x] Critical Failure`. Try to decompile the file using ghidra but got me dizzy..&#x20;

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2FLVJAWqIaqzbWpSsN7iU0%2FVirtualBox_kali-linux-2023.1-virtualbox-amd64_15_12_2023_18_30_08.png?alt=media&amp;token=1cb29233-7491-4d22-be21-d85a046d7d5e" alt="" width="455"><figcaption></figcaption></figure>

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2F75d0DK3LfIldDUq1GtOG%2Fghidra.png?alt=media&amp;token=77a1ec48-c0a7-4279-800f-44e2e7aab582" alt="" width="454"><figcaption></figcaption></figure>

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2FAtrw9oCUvdrVtvSzo4X0%2Fgethandle.png?alt=media&amp;token=1cbe94b0-b882-4c94-90ec-068916be6614" alt="" width="476"><figcaption></figcaption></figure>

Then I use `ltrace` and at the start of the execution of the binary file showed some kind of calling library? Then it will ask the user some input.  After going through each line, I saw the flag!

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2Fmk5yb6YARhuBSDQoN90K%2Fltrace%20new.png?alt=media&amp;token=2adf95a2-f1fa-421e-b2b6-6453a151f766" alt="" width="563"><figcaption></figcaption></figure>

<figure><img src="https://906050983-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNUYCtlc0k8qWwmB2FmiA%2Fuploads%2FC4wYhF7v1lzuhwK2Mygo%2FUntitled%20design.png?alt=media&amp;token=b4f69e9b-fce8-46ed-abff-84612d21ee6f" alt="" width="563"><figcaption></figcaption></figure>

Flag: `HTB{st4t1c_l1b5_but_c00l3r}`