Most of the information here is for Warzone 3.1 and above.
cam1out5 transcript
Overview
This briefing highlights several pertinent observations regarding the NEXUS Intruder Program...File location
 sequences.wz / sequences / cam1 / cam1out5.ogg
Sequence
...NEXUS [Intruder Program]Â then removed itself from the system, destroying its memory banks and removing all traces of it's external connections. We are not sure what NEXUS is, or who or what is directing it.
Initial research links the NEXUS Intruder Program with The Reed Corporation, the developer of the Synaptic Link.
We have ascertained that NEXUS supplied the New Paradigm with most of it's technology.
Whatever Nexus is, it's more than a computer parasite. It has technology... and weapons. It knows about us and it is not friendly.