Tags: emoji exiftool metadata 

Rating: 5.0

# Emoji Hunt

![Challenge Description](https://raw.githubusercontent.com/acoozi/CTF-Writeups/main/SquareCTF2022/ressources/emoji_hunt_challenge_description-0.png)

As in the challenge description written, there are a couple of emojis that are containing parts of the flag.

Looking at the slack workspace and searching for the keyword flag shows us some emojis named as :he-brings-you-\*, as well square-ctf-\*. Both show a flag on the emoji.


Downloading some of them and taking a look at their metadata using exiftool it shows that there is an entry " FL :" followed by a short string which has to be part of the flag.


Unfortunately, the emojis downloaded don't have the whole flag, which means that there has to be more custom emojis containing parts of the flag.

Now we need to download all custom emojis and check their metadata. I decided to choose a chrome extension called [Save all Resources](https://chrome.google.com/webstore/detail/save-all-resources/abpdnfjocnmdomablahdcfnoggeeiedb?hl=en) which adds a register card to chromes developer tools and lets us download all resources that where loaded by our browser.

After we installed the extension, we go to slack and download all emojis. We only need to make sure that we scroll through all the custom ones to have the browser load them, so the extension can download them all.

1. Check the sources register card in dev-tools. There you can see the page emoji.slack-edge.com. Expanding the entry and the folders beneath that’s where the emojis are stored. The path is as follows <page/workspace/emojiname/emoji.png>. While it’s not needed here we can check if emojis are loaded as we scroll through them and it also will be how the emojis will be stored after we download them.


2. Now that we have scrolled through them, we move to the extensions register card and save all resources, which creates an app.slack.com zip file with the content.

![extensioin: save all resources](https://github.com/acoozi/CTF-Writeups/blob/main/SquareCTF2022/ressources/resources_saver-0.png)

After unzipping the file, the folder app.slack.com"/emoji.slack-edge.com"/TDJ19TTMW/ contains all emojis in subfolders. With a one liner we can then search for the needed metadata and get the flag.

![oneliner & flag](https://raw.githubusercontent.com/acoozi/CTF-Writeups/main/SquareCTF2022/ressources/oneliner_flag-0.png)

Original writeup (https://github.com/alekszivko/CTF-Writeups/blob/main/SquareCTF2022/Emoji%20Hunt.md).