This time we’re walking through the challenge called My Letter from the forenscics category.

• Category: Forensics
• Points: 80

You can find full problem info here, together with the original file.

Solution

Firstly, let’s view the file with a docx viewer like Libre Office Writer.

As you can see, some of the letters are bolded. Let’s delete the rest and see what we’ll get.

Just a troll :D

But let’s remember that docx is actually made of a zip, so let’s change the into my_letter.zip and unpack it. Maybe its content will show us the flag?

An image? Let’s take a look.

Tools

Libre Office Writer

References

http://www.forensicswiki.org/wiki/Word_Document_(DOCX)

Keep learning and stay safe! ~ W3ndige