Installing Kali Linux as a Virtual Machine in Virtual Box

[critikaster]

I doubt this is the issue, but I can tell you, you don't need the 'sudo' you're running as root already.

It seems to me that your sources.list is messed up. They should look like this: http://pastebin.com/5cUsiBZr

Thanks Eric, adding these two lines did fixxed it it for me indeed:

deb http://http.kali.org/kali kali main non-free contrib
deb-src http://http.kali.org/kali kali main non-free contrib