Problem: This is a really weird text file TXT? Can you find the flag?
File: THE_FILE
Solution: If you opened the file in a hex editor you’d notice the extension is 89 50 4E 47 meaning its a .png file. Or you could have attempted to open it as a txt file and noticed the PNG part with the unreadable characters. So change the file and then you can open it.
Flag: picoCTF{now_you_know_about_extensions}