Ubuntu 20.04 being hacked

I agree with previous answers you should sanitize you PC and other devices, i mean a full factory reset of routers and other devices to avoid present configuration checking and also check the other computer devices attached to the same network, remember that a professional hacker doesn´t just compromise the prey but also the complete environment it means that maybe even the USB devices connected to the compromised machine could be infected.

One good way to start is to securize your computer formatting all and installing all from zero using a firewall and even an antimalware solution available for Linux, and the same with the other computers of your network.

And as a programmer you can design a good firewall script to avoid future issues, the IP tables/nf tables sintax is not so difficult and wont be complex for a developer machine (Servers and NAT is at another level trust me).

Take a look of CIS controls v8 they will give you a clear picture of cybernetic security measures for the enterprise but many of them are useful for the home use too in fact the version 8 is focused in telework.

And be careful with websites previously visited from the compromised machine, the hacker could be sniffing and capturing your passwords weeks ago, and so for browser password manager.

This is my humble advice, good luck.

P.D-Zero trust....that´s the answer today.

There's no simple answer to this. It's most likely you've installed a virus / malicious software that's used to hack your computer .

Your best best it to wipe the system, scan for viruses & check what programs you've installed before to avoid repeating the same mistake .

I'd also check all attached devices & router settings to make sure the hacker didn't leave a backdoor into your network .