For the purist that does not trust any other computer you can simply turn it off and get your updates directly from Microsoft’s servers (or a Domain Windows Server Update Service). This is the model that seems to have the least questions for security and we imagine that many people will chose this one.
For the braver people out there, there is an option to be able to grab updates (or parts of updates) from the PCs around you on the trusted LAN. This provides some security as the systems you are getting the files from are inside of a trusted network and should be safe… should be. That is the problem, what would happen if one of these trusted systems was infected with malware? Would it be able to propagate through this system and spread? Right now we do know that you can poison a torrent swarm and there are multiple bits of malware that spread through the P2P protocol. Still if you keep your systems clean you should be ok.
What is interesting is that Microsoft apparently allows for a third option that is much like the Nightmare skill level in the original Doom. This options allows you to receive updates from any computer. Yup any computer. It does not matter if it is inside your trusted network, out on the open internet or in a bad guy’s basement. You can get your updates and files from all over the place. What could go wrong?
I can picture malware developers already looking into how to insert malicious code into this system to infect anyone dumb enough to enable this level of heroic stupidity. We are not even sure why Microsoft would even add this in to be honest. There are too many ways to poison this type of system for this to be a good idea. We hope that this is not something that stays in Windows 10 or that can be removed or is at least is disabled by default. If not Microsoft will have hit a new low for their security standards…
Thankfully Windows 10 is not ready to launch and has a long way to go before it hits the streets. If enough people give negative feedback on this is might just go away… or maybe Microsoft will treat this like Metro/ModernUI and shove it at everyone despite how much people do not like it.