Just had an email from the co-ordinator of the local LUG (Linux User Group).
You should look at disabling snapd.
(Mod Note: Corrected Link)
Disabling Snapd in Ubuntu 20.04 and 20.10
Anyone can gain control of your own machine using snapd. (As they can with telnet and finger.) Also a good idea to install sshguard. Install with:
sudo apt-get install sshguard iptables-persistent ufw
(Don't bother with downloading the source ...
[With acknowledgement to ShefLUG co-ordinator]