Well, an anti-virus isn't too hard when you know that the code will be a lot more simple than how it is now.
Yeah for that once simple virus. To build a antivirus you need to know. How that virus works, what it does, how it's coded, what it changes, and how it replicates. This is just one virus your talking about there being thousands of viruses being made in that world just like today.
You would need a extensive ingame lab just to be able to analyse them all. Then come up with patches on how to combat and get rid of these viruses and then package that into a nice little program which then has to be update every so often with a database which contains all the viruses and said fixes. And that's even the most basic part of it. You need someone to build and maintain the database someone to patch update and keep the antivirus in good nick and stop that antivirus from being used as a exploit.
And so so much more stuff. You would need a team constantly working on it, while a fire wall in its most simple of terms can be made to stop any rogue code from doing anything unwanted e.g .
Does this program alter code for oxygen systems?
Yes?: stop code from running and inform the user what program has tried to interact with this function
No?: let program run
Also I agree with having sleeper in all major guilds, we can then get them to upload horrible viruses.
I also take it our group will only consist of Bay12 people for added security, and will we have a TS channel ? If not then I can always set one up for us.