It's shame that the two main public banks in Brazil require a weird virtual machine for their services using GNU/Linux. I use to need it here and there, so...
Building the package:
apt-get install fakeroot java-package fakeroot make-jpkg jre-7u45-linux-x64.tar.gz sudo dpkg -i oracle-java7-jre_7u45_amd64.deb
The above was enough to have Iceweasel working.
ln -s /usr/lib/jvm/jre-7-oracle-x64/lib/amd64/libnpjp2.so /opt/google/chrome/plugins/
That's all. Hope you never need it.