Level goal

The password for the next level is stored in a hidden file in the inhere directory.

Login

ssh bandit3@bandit.labs.overthewire.org -p 2220
MNk8KNH3Usiio41PRUEoDFPqfxLPlSmx

Doc

man (1)              - an interface to the system reference manuals
usefull ls flags:
-a, --all
              do not ignore entries starting with .
-A, --almost-all
              do not list implied . and ..

Solution

Use ls -a in order to see files precedented by .`s and navigate to the file then cat the file for the flag. 

bandit3@bandit:~$ ls
inhere
bandit3@bandit:~$ cd inhere/
bandit3@bandit:~/inhere$ ls
bandit3@bandit:~/inhere$ ls -a
.  ..  ...Hiding-From-You
bandit3@bandit:~/inhere$ cat ...Hiding-From-You
2WmrDFRmJIq3IPxneAaMGhap0pFhF3NJ