What I’m about to say will probably make some of the more hardcore Apple and Linux users cringe down to their bones but stick with me… I’ve got good reason:
That’s it. One word. A zombie computer is one that can be controlled and made to do things by a third party without the owner knowing. It’s zombie in the voodoo sense, not the George Romeo genre of bran-lusting cripples.
These zombies can be used to attempt hacks on other computers on the internet, disable sites, support phishing scams or just send spam. Some estimates have put 50-80% of spam being down to zombie computers.
Of the various problems with Windows XP and Internet Explorer, by far the most potent was that the default account setting was an administrator. When you ran things they had full access to your entire computer.
This is fine when you’re running legitimate “good” software, but when you browse a page in IE and it loads malicious code, that code can execute things on your computer with your accounts privileges — total system control.
Vista has addressed this issue to some degree. The default user account is still an administrator (as far as my experience with it has shown me) but it is a limited administrator. Whenever something happens that touches something in the system-core, a human has to acknowledge and allow the request.
This means there’s far less scope for drive-by installs of viruses, turning your machine into a zombie in the process.
So if everybody migrated away from XP tomorrow, just imaging now little spam we might get. The world would take back control of the internet from cyber-criminals.
Ideally, everybody would move to Linux and considering the speed Ubuntu is progressing at, that could well happen by the next major release of Windows.