Scary, isn't it?
Want to be protected?
Here are some simple steps and you're saved
just create %windir\perfc.dat file with read-only permission (right-click file and go to Properties then check read-only attribute)
THAT'S ALL you need to protect yourself against Petya.A virus.
How that works?
Virus Petya.A encrypts your harddrive and it's really hard to decrypt.
it creates file perfc.dat in your \Windows folder
If you create empty file and make it read-only, virus simply cannot create and modify this file!
As simple as that!
Tested it yesterday, by clicking virus file that was attached in the strange e-mail from PayPal