Basics of CLI, Services in Kali (SSH) and how to change your motd (Banner)

Linux basic command refresher:

**echo **- display a line of text i.e

echo "hola"

Include text string "foobar3" into file

echo foobar3 > file.txt

Include text string "foobar2" into next line of file.txt

echo foobar2 >> file.txt

If we ran cat against file.txt, it would look like this:

foobar3

foobar2

**Kali Linux Services **

HTTP via Apache2

Enable service on startup

systemctl enable/disable Apache2

Toggle service On/Off

service apache2 stop/start

Note: HTTP files are stored at /var/www/html

View all files in /var/www/html with -la flag for display a list and all hidden files in the present directory

ls -la /var/www/html

Present directory can be shown with:

pwd

SSH via _ssh_** **

enable ssh service on startup##

systemctl enable/stop ssh

toggle ssh service On/Off

service ssh stop/start

**Configure SSH on Kali to allow login w root password (insecure) **

1. In '/etc/ssh/sshd_config' replace 'PermitRootLogin without-password'by 'PermitRootLogin yes'

2. Restart your ssh daemon

service ssh restart

3. Change Kali default ssh keys to avoid MITM attack:

4. Move the default Kali ssh keys to a new folder:

cd /etc/ssh/

mkdir default_keys

mv ssh_host_* default_keys/

5. Regenerate the keys

/etc/ssh# dpkg-reconfigure openssh-server

6. Verify Hashes are different

**New Keys **

root@kali:~/Desktop# md5sum /etc/ssh/ssh_host_*

**Old keys **

root@kali~/Desktop# md5sum /etc/ssh/default_keys/ssh_host_*

7. Restart SSH service

systemctl restart ssh.service

8. SET MOTD for extra badassness (Essential)

sudo nano /etc/MOTD

9. Remove current MOTD (Possibly Wack)

rm /etc/motd

11. Don't forget to backup ssh config !

cp /etc/ssh/sshd_config /etc/ssh/sshd_config_backup

**12. Change port ssh listens on **

find '#Port 22' change 22 to desired TCP port.

**13. Restart openssh **

systemctl restart ssh

14. Profit!