Even if AVG blocks this virus at the moment, it's never sure they will block a new variant of the program, or another ransomware virus, or - in fact - any new virus. So it's not a good idea to trust that an antivirus program (any antivirus program) protects you for the full 100%.

Things to do:
1. Regularly backup the things you don't want to lose to an off-line medium (external disk, USB-stick, a spare PC on your home network that's usually turned off, the cloud). Then if the original is damaged in some way (either by a virus or by a hardware failure or whatver) you can get the copy from the backup when your PC is up and running safely again.
2. Be careful when connected to Internet. Don't visis shady sites, don't do illegal downloads and P2P-downloads, never click on a link a mail that you don't fully trust.