I had a similar issue with the corrupt download or unable to find the file to unarchive. 
It appears this is an issue related to 64 bit arch vs 32 bit executable. Most likely those experiences this issue are in the same boat I was trying to extract this on a 64 bit system. 

Run the following command (in Ubuntu) will install the 32 bit libraries needed to run these VM's.
sudo apt-get install ia32-libs

I was able to extract this after installing these libraries.
I hope this helps. (No other software was required)