Yes unfortunately accounts can be hacked by keyloggers what has been installed, and they read all you type, but in order to such being possible, you have to had been on a website eg. where you have got the keylogger in first place.
Such sites are eg, searching for cheats, hacks etc for your games, or specifically for PG.
Those sites are ALL illegal sites, and this might be the price you have to pay for trying to break the PG rules, or searching for a way to do that.
The best way of protecting yourself was post in the previous post in this thread by Delloda,
I am aware of that any screenshots you may have, the hacker might obtain after he has hacked the account as well, so that is not secure at all.
What you can do, is to make a serie of screenshots of your inventory, then you save each file as a gif what makes the file of minimum size, then you zip it, and you can send a copy of it to a trusted friend what you have in the game. If something happens, the friend can come forward with the copy, and you with the original and both send this separately to the support.
Avoid adding anything of your login details within this zip, only the screenshot, and a notepad with your Pilot name, and server you play on.
If you both send it to the support, be sure to write in the email the friends Pilot name and your own, and what, and who's issue you are dealing with, a detailed description of what has happened, and how, and when.