CounterACT

ForeScout's CounterACT took the most time to install and configure. It works much like a network sniffer looking for "malicious sources". These are devices that appear to be sending non-standard network traffic. CounterACT therefore protects a network from zero-day attacks because the filtering is not based on signatures but rather on a deviation from normal network information. The appliance also includes a vulnerability-scanning service that can be used as an automated or manual process launched by the administrator.