GVTs - wearegvts.com
OtterCTF - Misc - “ReCurse”

There is a zip bomb under the a.zip.
We didn’t even bother to run a bash script. Basically created two folders named 1 and 2.
Run the commands dozens times and saved the output to a file because we believe file names has to meant something.

unzip 1/*.zip -d 2/ && rm -f 1/*.zip
unzip 2/*.zip -d 1/ && rm -f 2/*.zip
cat result |grep Archive|cut -c 13-|cut -c 1|tr -d "\n"

Parsed file names looked like this:

Its a base64 decoded and equals to:

The last zip file which is w.zip requires a password and we can see the file name archived.
It says Email Me This.

So, zip password must be in the URL given as base64.

There is a seller profile in the URL with data follows:
Name:  Bob King  
User Review

User Review href includes a e-mail address:

This is the password of the w.zip file and EmailMeThis.txt contains the flag: