The Root of All Evil

First things first...

I tried to connect to the host but it just rejected the conection asking for a private key.

Getting access

The challenge gives a pcap file to use so I guess that somewhere in there should be a private key. Searching in the pcap file for the string private in the packets data part revealed the Luciafer private key!

Give me my flag!

We can now connect to the machine and get the flag under /home/luciafer/Downloads/flag.txt:

flag{Lucy-a-FUR-G0T-R3KT-by-the-BLUZers-CLUB!!!}