Table of Contents

Get a detailed walk-through of the HackTheBox Crypto Decode challenge. Given two strings of information, this article guides you through the process of decoding a Fernet cypher and a Malboge cipher to reveal the flag. Utilize tools provided by asecuritysite.com and base64decode.org to achieve the solution.

Provided Files:

In this challenge you are provided two strings of information.

993gmULBNujjrZCDev3W8kAVaLkXiyHhCL3500188bA=

and

gAAAAABboRUb0FsuiYBk1tsXRDr6KAzU1xrNSUv7grB-G-dAEeyqj99kUebz466I2VcH5xDa5HEc5KkbgTklQ7tm9JCRPlJtRng1Ns3VEvbrk7B835OINfPnRbc-UIOnnCmW3CgMdMtf5wGLN299AZEzxIvuy71WC5d9xJDchyiORycuzCth95-4nTKphlNQQ2ko3DX72RxWeEjwt3mavnFXqcOCkGxUhJYmFltz_6ND56VGTrXZi_CK5xLODOX4sj1GNwN_CrU3sJ0obTdA2wF5OaDZLbA1GBPfK0PDlC9WxoUf85K0tFXKfqbt3c5YqtqfytNG5gTkbDFM2NjE7BveBf1DP9ca8g==

Walk Through:

At first glance it appears this is some sort of key and some cipher text. After searching around, you’ll find that it is a Fernet cypher. Asecuritysite.com has a great tool to decode it for you.

The plain text from the above information gives you a base64 encoded string

RCdgTl45OFs8O3tGMlZVNTRRPythcUw6bVxJNmlYJmYkMEBSeFBfdSldeHFwdW5tM3Fwb2htZmUrTGJnZl9eXSNhYFleV1Z6VFNyUVZVTnJMUVBPTkdrS0QsSEFlKERDPDtfPz5+fTVZOTg3dzUuUjJyMC8oJyZKKikoJyYlfHtBeX53djx6eXhxWTZ0c1VUcG9oLnk=

To decode this, we’ll use the tool provided from base64decode.org

Decoding again gives you the following:

D'`N^98[<;{F2VU54Q?+aqL:m\I6iX&f$0@RxP_u)]xqpunm3qpohmfe+Lbgf_^]#a`Y^WVzTSXQVUNrLQPONGkKD,HAe(DC<;_?>

This was a new one for me. But you’ll find after some careful research that it is a Malboge cipher. Decoding it with this tool will give you the flag.

Flag Ex: 

HTB{x_xxx_xxxx}