Challenge Description
Hmmmm… the challenge description hints that we will be following a Forensics approach. However, this challenge is categorised under General Skills. We shall explore!
We first download the file given using wget <link>.
Downloaded file
The downloaded file is called challenge.zip. When we unzip the file, many directories and files are created in a directory called drop-in. Most files were created under a .git folder. This gives us a clue that our flag may be associated with Git, which is used in version control.
There is also a file called message.txt in the drop-in directory.
Contents
When I ran cat on the message.txt file, this string was displayed:
This is what I was working on, but I'd need to look at my commit history to know why...
Interesting… Let’s cd into the .git folder to check its contents. There are a few files and directories within this folder, such as COMMIT_EDITMSG, index and branches.
I first checked COMMIT_EDITMSG by running cat, and the file was indeed present in it.
Flag
picoCTF{t1m3m@ch1n3_5cde9075}