I did not bother to find out anything about LVM, because I'm going to bed right now. Just came from a hospital - it turned out to be something harmless.
Encryption does not help at all, if someone can read your password, and the password can be read if your computer is connected to the net when you are typing the password, or after that.
Antivirus programs do not help.
I hope you do not continue about this subject -- I am an expert here.