The Chai Open qPCR machine (https://www.chaibio.com/openqpcr/) is a great little democratizing molecular biology instrument. Unfortunately, the manufacturers shipped it with SSH and a default password with sudo access enabled! This means that anyone who can find the IP address of your qPCR machine can take it over and do whatever they want with it, including using it as a way to attack the rest of your network. Fortunately, this problem is pretty easy to fix.
This assumes you have access to a unix-like terminal (like the MacOS terminal). In short, you'll want to login to the machine, change the default password, and disable root login. For extra safety, I recommend contacting the manufacturer for fresh firmware image and flashing your firmware. That should clear out anything that's potentially been compromised. You'll need the IP address of your qPCR machine too, here we're calling it 10.0.0.100. The default username is debian and the default password is temppwd.
user@local-machine $ ssh debian@10.0.0.100
debian@10.0.0.100s password:<enter "temppwd" without the quotes>
debian@beaglebone:~$ sudo nano /etc/ssh/sshd_config
# this will pop up a text editor
# find the line that says:
PermitRootLogin yes
# and change it to
PermitRootLogin no
# then hit ctrl+x, answering "y" to save the file
debian@beaglebone:~$ passwd
Changing password for debian.
(current) UNIX password: <enter "temppwd" without the quotes>
Enter new UNIX password: <enter a new more secure password>
Retype new UNIX password: <enter it again>
# restart the ssh server to make sure that root login is disabled
debian@beaglebone:~$ sudo service ssh restart
# (you may have to enter the new password you just set)
...
# now you can log off
debian@beaglebone:~$ exit
user@local-machine $ # now you're doneIf you follow the instructions above, you should now have a much more secure Open qPCR machine!