Sharing writeups of CTF challenges and Machines
To solve this challenge, we need an understanding of references in headers. We will use this reference throughout the challenge. Q1. Only people who use the official PicoBrowser are allowed on this site! Change the user-agent to PicoBrowser. Q2. I don’t trust users visiting from another site. The Referer header allows a server to identify referring pages … Read More “picoCTF2021 – who are you? writeup” »
Description I’ve hidden a flag in this file. Can you find it? Forensics is fun.pptm Solution Let’s see what is hidden in the ppt file. OK, There are quite many files hidden. Let’s extract them. Then we get the directory called _Forensics is fun.pptm.extracted Let’s see what’s inside. Found the file hidden! What’s written inside … Read More “picoCTF2021 – MacroHard WeakEdge write up” »
Description Files can always be changed in a secret way. Can you find the flag? cat.jpg Solution Check out the details of the attached image file. exiftool can be used. Then, we get the result as below. License looks like base 64 encoded. Let’s decode it. picoCTF{the_m3tadata_1s_modified}
Description crackme.py Solution Check the source code of the python file. We can see there are two functions decode_secret() and choose_greatest(). At the end of the file, choose_greatest function is called. But, we don’t need this function. So let’s delete it. Instead, we want to use decode function. Also, we are given with the encoded … Read More “picoCTF2021 – crackme-py write up” »