# 2️⃣ Easy 300: Hack and Take a Break

<figure><img src="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2FT7WJYGq885h2uWPUWWnv%2Feasy2.png?alt=media&#x26;token=08143355-043a-4da9-af4b-153b325dc977" 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="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2FAvTl27HodT51c2X5wz5S%2Feasy2-1.png?alt=media&#x26;token=776c06a6-998b-4d52-a72e-62847024979c" 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="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2Fr8gOVfyxE363d6k4nqAT%2Feasy2-2.png?alt=media&#x26;token=0ca22cde-15be-47c6-915e-6b59d3cea38e" alt=""><figcaption></figcaption></figure>

Using rot13.com, I got the result below

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

<figure><img src="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2FKF8ahIv3o90SX1XTmO4h%2Feasy2-3.png?alt=media&#x26;token=8875a9ba-18dd-47d0-a067-f9c501ad1b28" 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="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2FQ9SkkAhc58tpoirOt8tu%2Feasy2-4.png?alt=media&#x26;token=9c304b5a-31c9-4127-bb4d-e7ce15c14d4c" alt=""><figcaption></figcaption></figure>

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

<figure><img src="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2F8kkhkhKdr7N03F3xj1T3%2Feasy2-5.png?alt=media&#x26;token=68a7c384-8859-4ec8-92e3-dd426f7aa453" alt=""><figcaption></figcaption></figure>

Then, I got a hex value below:

<figure><img src="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2F1oxitGiYXhfs5FCAaEjH%2Feasy2-6.png?alt=media&#x26;token=041a01ac-c9ed-4443-b138-a12efb13a3cb" alt=""><figcaption></figcaption></figure>

I decode it and got the following flag:

<figure><img src="https://382757542-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfAxmqRz869b0dQQ6DjHW%2Fuploads%2Fyxok38totlr0nixyA7MN%2Feasy2-7.png?alt=media&#x26;token=f732bfeb-677e-4ac5-a555-12337287dd24" 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.