my parrot os debian has been definitively hacked

Right. The keyboard was behaving strangely, and my single login was listed as session 2 on the taskmanager. Installing files led to multiple instances notifications. Eventually I put in a flashdrive and checked users and there were two separate instances using the same username. I think the issue started when I tried updating the system.

Anyways, I am paranoid but not unreasonable. I have tried reinstalling the iso but this does not seem to fix the issue. Advice?