I presented on a panel today at the European Information Security Summit 2015, entitled 'Should you launch an internal cyber attack?' We only had 45 minutes and I thought I'd share some of my thoughts, and what I didn't get to say, here. Firstly, as we all know, the concept of a network perimeter is outdated and there is a real blurring of whether devices should be considered internal or external these days. It's not just about BYOD , but most organisations provide laptops for their employees. These laptops get connected at home, airports, hotels, etc. Any number of things could have happened to them during that time, so when they are reconnected to the network, they may have been compromised. For this reason, it should be every system for itself, to a certain extent, in the network, i.e. assume that the internal machines are compromised and try to provide reasonable levels of security anyway. Secondly, the user is the weakest link. It has been said many times t...