VPC Changes

CUIT continually monitors changes made in the console to a handful of crucial AWS services. Virtual private cloud, VPC's, are included in this list as one of the essential items. Not every change is indicative of bad activity, however, it's important to keep record of them in the event an attack were to occur relative to VPCs. VPC's are the core of a network in the cloud and has the potential to be a highly targeted service. 

Many events take place in a VPC including network ACLs, creation/deletion items, and modifications of many configurations. Like any other service, best practice is to make sure each change is wanted with configurations created with security in mind.

https://aws.amazon.com/vpc/