Same Difference

Challenge

Solve this problem by connecting to the EasyCTF shell, either in your browser or through some other TTY.

We’ve noticed that a list of passwords has been modified. Compare the original master_copy.txt to the suspicious.txt and tell us what the password was changed to! The files are on the shell server at /problems/same_difference.

This can be solved only with the tools available in the shell. No scripting languages are required.

Solution

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$ ll /problems/same_difference
total 832
drwxr-xr-x  2 root root   4096 Nov  4 23:50 ./
drwxr-x--x 10 root root   4096 Nov  4 23:56 ../
-rw-r--r--  1 root root 420000 Nov  4 23:50 master_copy.txt
-rw-r--r--  1 root root 420000 Nov  4 23:50 suspicious.txt

$ wc -l master_copy.txt
10000 master_copy.txt

$ diff master_copy.txt suspicious.txt
8834c8834
< easyctf{17c85a939e5ee1b0b0e00ed7187d11f7}
---
> easyctf{60a57b3974029aa012e66b05f122748b}

Flag