In linux, it mostly just keeps you (or an application acting on your behalf) from accidentally doing something dumb.
In Windows, you can't install many kinds of software without running in an account as administrator, because you don't have write access to the program files or windows folders. The worst kinds of malware need to be able to write to these areas to worm their way into your system.
If you're not running as an administrator and visit a compromised site that tries to install something like a hidden keylogger to steal passwords, bank information, or credit card numbers, that install will likely fail. If you are running as administrator, that install has a much greater chance of succeeding. The same principle holds true for linux systems.
They key here is that anti-virus software doesn't even enter into. These days, antivirus software is your last line of defense, not your first. The order of importance that I use to rate security measures goes like this:
- Keep your system (including application software) patched
- Do not run as administrator
- Use other safe internet habits
- Run a firewall
- Have a good offline backup (in this case, offline means "not accessible to your normal file system", which might actually mean using an online service)
- Run antivirus software
In fact, if you're doing enough of the other items correctly, anti-virus software isn't really necessary at all. But the important thing here is that running as administrator is a no-no.
Thankfully, this is now the default state in Windows 7. Even if your account has administrator privileges, it still runs "sandboxed" and merely gives you the right to elevate for a specific application on demand.
3So in short: it's effing dangerous. – digitxp – 2010-12-04T18:18:46.030
Just looking at that command makes my stomach churn. – Paul Lammertsma – 2010-12-04T18:24:44.750