TL;DR
# cat /etc/apt/sources.list
Change occurrences of
deb http://ftp.us.debian.org/debian/ wheezy main contrib non-free deb http://ftp.us.debian.org/debian wheezy main contrib non-free
to
deb http://archive.debian.org/debian/ wheezy main non-free contrib deb http://archive.debian.org/debian/ wheezy-updates main non-free contrib