14 DAY TRIAL // The Free Software Foundation is a non-profit organization that has only one goal – to support the free software movement. Now it has deemed that all of Microsoft's software is actually malware.
Most of the Linux users don't really encounter the word malware in their day-to-day operations. It's not something that you need to actively protect against, the way the users of Microsoft products are doing. You can sum it up as a software that is built with the purpose of harming the operating system in various ways.
If you check the official definition on Wikipedia, for example, you will see that it is a little different from what The Free Software Foundation is saying, but you can be the judge of that.
“Malware means software designed to function in ways that mistreat or harm the user. (This does not include accidental errors.) This page explains how Microsoft software is malware. Malware and nonfree software are two different issues. The difference between free software and nonfree software is in whether the users have control of the program or vice versa.”
“It's not directly a question of what the program does when it runs. However, in practice nonfree software is often malware, because the developer's awareness that the users would be powerless to fix any malicious functionalities tempts the developer to impose some,” reads the gnu.org website.
The Free Software Foundation has made a bullet-point list with some of the things they say qualifies as malware. Even Linux users might have a problem agreeing with everything on the list, but it's their list (even though some of their problems with Microsoft are actually quite old).
The non-profit organization says that Microsoft has a backdoor in Windows that allows them to perform updates without asking the users about them, and they point out to the German government, which said that NSA had access to every Windows 8 computer.
Microsoft was also accused that the company informed the NSA about bugs before fixing them, and that they cut the Windows XP security fixes, with the exception of a few third parties that will pay large sums of money to keep the updates flowing.
This is pretty powerful stuff, even from The Free Software Foundation. We are accustomed with the organization making big claims, sometimes even about other Linux distributions. They even said that Ubuntu was filled with spyware.
Whether you choose to agree with The Free Software Foundation’s position is up to you, but it's worth noting that none of the Linux developers is acting in this manner towards Microsoft.