> For the complete documentation index, see [llms.txt](https://codingmace.gitbook.io/masterward/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://codingmace.gitbook.io/masterward/ctf/2017/backdoor-2017.md).

# Backdoor CTF 2017

## Dead-PNG-2 - ?? \[300 pts] \[Not Solved]

> n00b accidentally found a corrupted zlib/png file, help him to recover the secret code from the file.

{% file src="/files/-MdYy01ynx4OhDWubRfI" %}
Corrupt
{% endfile %}

Solution:

Flag:

## Complex RSA - Crypto \[200 pts] \[Not Solved]

> n00b heard that single RSA encryption can be cracked sometimes due to bad implementation, so he encrypted the message twice.\
> See if you can break it.

{% file src="/files/-MdYypXCXIbH9Mj-5JRx" %}
Complex RSA
{% endfile %}

Solution

Flag:

## ECB - Steg \[150 pts] \[Not Solved]

> n00b learnt about ECB and has encrypted some images with it.\
> Can you find the flag?

{% file src="/files/-MdYwnIavp9i0Z6k\_jXN" %}
img1
{% endfile %}

{% file src="/files/-MdYwqFPjLbP-kn2db6f" %}
img2
{% endfile %}

Solution

Flag:

## ImageRev - Crypto \[200 pts] \[Not Solved]

> Reverse the encrypted file and recover the flag

{% file src="/files/-MdYyxroayZRH8CGnRkE" %}
Encrypted
{% endfile %}

Solution

Flag:

## NoCalm - Rev \[350 pts] \[Not Solved]

> h3rcul35 and starlord were having a heated conversation and to c00l down the furious starlord, h3rcul35 gave him a binary and said "The binary takes each 'character' byte of the flag as argument. Given this info, grab the flag. I hope you dont get angry :P". \
> Show h3rcul35 that you stayed c00l by finding the flag.

{% file src="/files/-MdYz3fbbILA2PpahsPU" %}
Challenge
{% endfile %}

Solution

Flag:

## Stereotype - Crypto \[300 pts] \[Not Solved]

> n00b is so sure that no one can crack his message and in this foolishness he even provided a part of plaintext. \
> You know what you have to show him

{% file src="/files/-MdYzAAnW-ztXWIh7pc0" %}
Text Files
{% endfile %}

Solution

Flag: