Thank you for this information!
The decompression bomb was a bit scary tough. It kept activating Avast. After half an hour scanning (with increasing noise) the scan-progress still remained at 0%. And the MyFile.exe virus emptied my W8 folder, there was only this ‘MyFile.exe’-file in the W8 folder.
This year I needed help to clean my computer 3 times, this was expensive. I don’t want this to happen again. (I already paid for Avast!)

For about 4 monthes my computer worked well.
But now I noticed another weird thing: MY HOTMAIL ACCOUNT IS HACKED! And this Hotmail account is linked to Avast.
So my main concern is now: to unlink Avast-Internet-Security from this hacked Hotmail account.
I think I need your (Avast) help to do this. I hope there is a way to solve this…