Windows remains the most widely used operating system for businesses, and Mac OS (NASDAQ: AAPL) is used by some, but neither program was built with security foremost in mind. Both operating systems were built to run programs without much input from the user, and that's a big reason our world is awash in malware, Farhad Manjoo writes in a post at Slate.

Both Windows (NASDAQ: MSFT) and Mac OS allow applications to access a computer's file system more or less as a default, Manjoo writes. They will "run anything you find online, and once the program is running, it can do almost anything." Even though hackers commonly target Windows, it wouldn't take them long to make Mac OS the target if a critical mass of business started using that operating system instead, he argues.

The advent of operating systems built for the web, such as Google (NASDAQ: GOOG) Chrome OS, the iPhone OS and Android, is changing the whole attack framework, however. The new systems were built with an eye toward security, making it harder for hackers to run malware on them, Manjoo maintains. The new systems have built-in restrictions on what applications can do. They cannot automatically operate in a way that would have an adverse impact on the operating system or other applications. On Android, an app must "declare its intentions" before it runs, and it can access only a given set of functions and files.

"[T]he difference between Android and Windows is the difference between having a lock on your door that could be picked and keeping your door unlocked," Manjoo writes.

At the same time, the restrictions on the apps may limit the user's activity, he writes, adding that the iPhone provides a good example: "The stuff that makes the iPhone OS safe is also what allows Apple to arbitrarily decide what you can and can't do with your phone." 

For more, see:
-Farhad Manjoo's post at Slate

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