Tags: forensics base64 apktools mobile android
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Orignal writeup: [here!](https://www.abs0lut3pwn4g3.cf/writeups/2019/03/05/bsides-ctf-Blink.html)
Blink
Description
Get past the Jedi mind trick to find the flag you are looking for.
We are provided with a blind.apk file.
On installing the app on a mobile, we see this:
![mobile ss](https://raw.githubusercontent.com/Eshaan7/BSidesSF_CTF_2019_datadumps/master/50_blink_COMPLETE/appMobileSS.png)
Then I used apktool to decompile it.
apktool d blink.apk
Going into the smali folder created by apktool
blink/smali/com/example/blink
There’s a `r2d2.smali` file. Inside there’s a string of base64 encoded image.
![r2d2.smali](https://raw.githubusercontent.com/Eshaan7/BSidesSF_CTF_2019_datadumps/master/50_blink_COMPLETE/r2d2img.png)
I saved the string to `blink_r2d2.txt`
cat blink_r2d2.txt | base64 -d > flag.png
On decoding the base64 string, and we get an image and the flag.
![flag.jpg](https://raw.githubusercontent.com/Eshaan7/BSidesSF_CTF_2019_datadumps/master/50_blink_COMPLETE/flag.jpg)