Has Pesterchum Been Hacked?

[SixMinusSix]

About twenty minutes to half an hour ago I was suddenly kicked off my handle and got a pop up message that said it was registered and that I couldn't use it and that my handled had been changed to "YOU ARE BEING HACKED". I immediately closed Pesterchum, disconnected from the internet and shut down my machine. I'm using a different internet connection and switched to a different machine but I haven't opened Pesterchum again. That message has me terrified. I saw on the forum linked in another issue that somebody else has had the same experience. What's going on?