Tags: shell 

Rating:

For a better view check our [githubpage](https://bsempir0x65.github.io/CTF_Writeups/AngstromCTF_2022/#amongus) or [github](https://github.com/bsempir0x65/CTF_Writeups/tree/main/AngstromCTF_2022) out

![https://raw.githubusercontent.com/bsempir0x65/CTF_Writeups/main/AngstromCTF_2022/img/amongus.png](https://raw.githubusercontent.com/bsempir0x65/CTF_Writeups/main/AngstromCTF_2022/img/amongus.png)

As the first challenge we got a tar.gz package with 1000 files which seems on the first glance just to differ based on the name of the file. So we first ran
```console
└─$ md5sum *
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_00b82a142fc1}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0b3dfaec90a9}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0bad8f058410}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0c608487aef8}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0c24263013ad}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0cb13db7de98}.txt
56f9fc5e1e5e02492fb9d5e7b8dbe13b actf{look1ng_f0r_answers_in_the_p0uring_r4in_0cd4025ea71b}.txt
```
to see if they are really all the same. So since its 1000 files its to tedious to search for the one different file. Therefor we just grep out the ones which are already duplicates, which results in
```console
└─$ md5sum * | grep -v "56f9fc5e1e5e02492fb9d5e7b8dbe13b"
668cb9edd4cd2c7f5f66bee312bd1988 actf{look1ng_f0r_answers_in_the_p0uring_r4in_b21f9732f829}.txt
```
the one we were searching. Voila nice little challenge for the shell and our first points. (((o(*°▽°*)o)))
P.S: The solution commands were executed in the folder out of the unzipped tar file.

Original writeup (https://bsempir0x65.github.io/CTF_Writeups/AngstromCTF_2022/#amongus).