Something makes all browsers on any operating system or computer of my home network to open random web pages and ask to install a Microsoft protection of some kind, what could do that?
It send random links like:
http://results.google-analytics.com/
http://wellaction.com/?q=fine+silverware
redirects to http://crazyfastcash.com/?query=fine+silverware
Yes, there are many trojans that try to duplicate the Microsoft Windows Update and Windows Defender UIs. They are especially effective if you run your browser full-screen; they really do look like the real thing. Also, Googling the name will not help because they use Microsoft's names and logos.
The best way to tell if it's a fake is to minimize the browser; if the "virus alert" disappears, it's a fake.
Microsoft has a web page showing some of these fake programs at http://www.microsoft.com/security/antivirus/rogue.aspx.
If you see one of these things, tell the web site.
How do you connect to the internet?
Given it's any OS and all computers it sounds like there's something wrong with your router or gateway PC.
What's the URL of the site(s) you get? You can enter them as text if you don't want to link to them.
It's very strange that all OS are affected, so it must be something on your router or internet connection.
If you connect through a gateway computer you should restart the computer in safe mode and run antivirus and spyware to check for DNS changer viruses.
If you have a connection through a wireless router, it may be compromised. Try changing the password for the router and see if the problem continues.
Just to be safe I recommend scanning all the computers in your home for viruses.
It's best to actually research the 'Microsoft protection' program that it's detailing. Try Googling the name of it to see if it's malware (note: it's best to go to recognisably named websites and look at any that are paid for at the top - they are usually reputable).
Though it sounds as if that if it is malware, it's something in your router, or maybe on a bit of hardware, like a shared USB key for it to be on more than one computer. Or maybe everybody went on the same website and got infected, but it does sound like malware at the moment, though you will have to research it more to properly find out
Sounds like an ARP spoofing malware if it is affecting all computers on your network. First isolate the computer that is sending out the ARP attacks, then either wipe and re-install the OS clean or get a really good scanner that can detect ARP malware (I'd probably just wipe and re-install the OS).
