> For the complete documentation index, see [llms.txt](https://ctf.laet4x.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ctf.laet4x.com/ctf-2022/rootcon-16-pre-qualifier/2-easy-300-hack-and-take-a-break.md).

# 2️⃣ Easy 300: Hack and Take a Break

<figure><img src="/files/VgQzlGwk7P072uSLIqFV" alt=""><figcaption></figcaption></figure>

The challenge pointed to CSP Bank, a Firebase Appspot Storage and BeVigil for indexing and research. Following the same process from the other challenge, wherein a constant.java file has list of strings, there I got the clues connected to the firabase storage. As shown in the image below, there is another link we have to check.

<figure><img src="/files/BKBe62j8gptAwo2FW4PB" alt=""><figcaption></figcaption></figure>

Upon visiting the link, what I got are scrambled texts which at first glance don't make any sense. Then I noticed in the URL wherein the file title is "rotated.json" which reminds me of rot13 cipher. This is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the alphabet.

<figure><img src="/files/HawVBhT6rPMQmJ9zF6K3" alt=""><figcaption></figcaption></figure>

Using rot13.com, I got the result below

```
"Name": "Unlimited Free",
"Developer": "support@unlimitedfree.com"
```

<figure><img src="/files/r8fZnoXy236n5ZasjUZd" alt=""><figcaption></figcaption></figure>

The results return one readable name and developer's email, **Unlimited Free** / **<support@unlimitedfree.com>.** Back to BeVigil, using the found credentials, and this time with the Advanced Search, I got the following results.

<figure><img src="/files/535gmPoVvTZqjq0GOa9o" alt=""><figcaption></figcaption></figure>

I click at Strings -> Unknown High Entropy String -> sources/com/intl/unlimitedfree/internal.java

<figure><img src="/files/rvHGM6VwKUEWxn5SWPoV" alt=""><figcaption></figcaption></figure>

Then, I got a hex value below:

<figure><img src="/files/9UCrcyWh4dd7A9XEXS1J" alt=""><figcaption></figcaption></figure>

I decode it and got the following flag:

<figure><img src="/files/646Mlbh0LY4of25hqcGC" alt=""><figcaption></figcaption></figure>

Conclusion: I learn how to use BeVigil, sometimes I'm lazy in doing deep checking/investigation of links and encoded strings but I just realize that those fundamentals in CTF are very important. Being familiar with encoding is very important too when it comes to CTF.