Briefing
ls -l shows a permissions column like -rw-r--r--. Read it as three groups: user, group, others. A file that is rw-rw-rw- (octal 666) can be written by *anyone*. That is a classic security smell.
List the directory in long form and find the file that is too permissive.
Objective Find the one file whose permissions are rw-rw-rw- and read it.
Stuck?
Take it one step at a time. Ask for a hint here, or type help in the terminal to
see the commands this challenge is about. Typing hint works there too.
That is every hint. If you are still stuck, run help in the terminal.