UPDATE 2013/12/11 - These scripts are for Bro 2.1 only. We've released Bro 2.2 and included an updated version of the APT1 scripts written for Bro 2.2. Please see:
http://blog.securityonion.net/2013/12/bro-22-and-elsa-15-packages-now.html
sudo apt-get install -y git
cd /opt/bro/share/bro/site/
sudo git clone git://github.com/sethhall/bro-apt1.git apt1
echo "@load apt1" | sudo tee -a local.bro
sudo broctl install && sudo broctl restart