Although all of the open source tools which make up Malcolm are already available and in general use, Malcolm provides a framework of interconnectivity which makes it greater than the sum of its parts. And while there are many other network traffic analysis solutions out there, ranging from complete Linux distributions like Security Onion to licensed products like Splunk Enterprise Security, the creators of Malcolm feel its easy deployment and robust combination of tools fill a void in the network security space that will make network traffic analysis accessible to many in both the public and private sectors as well as individual enthusiasts.
In short, Malcolm provides an easily deployable network analysis tool suite for full packet capture artifacts (PCAP files) and Zeek logs. While Internet access is required to build it, it is not required at runtime.
For a TL;DR example of downloading, configuring, and running Malcolm on a Linux platform, see Installation example using Ubuntu 20.04 LTS.