Binary package “bro” in ubuntu xenial

passive network traffic analyzer

 Bro is primarily a security monitor that inspects all traffic on a link in
 depth for signs of suspicious activity. More generally, however, Bro
 supports a wide range of traffic analysis tasks even outside of the
 security domain, including performance measurements and helping with
 trouble-shooting.
 .
 Bro comes with built-in functionality for a range of analysis and
 detection tasks, including detecting malware by interfacing to external
 registries, reporting vulnerable versions of software seen on the network,
 identifying popular web applications, detecting SSH brute-forcing,
 validating SSL certificate chains, among others.