Nonfree (proprietary) software is very often malware (designed to mistreat the user). Nonfree software is controlled by its developers, which puts them in a position of power over the users; that is the basic injustice . The developers and manufacturers often exercise that power to the detriment of the users they ought to serve.

If you know of an example that ought to be in this page but isn't here, please write to <webmasters@gnu.org> to inform us. Please include the URL of a trustworthy reference or two to serve as specific substantiation.

Back Doors

DRM

Digital restrictions management, or “DRM,” refers to functionalities designed to restrict what users can do with the data in their computers.

Ebooks “bought” from Microsoft's store check that their DRM is valid by connecting to the store every time their “owner” wants to read them. Microsoft is going to close this store, bricking all DRM'ed ebooks it has ever “sold”. (The article additionally highlights the pitfalls of DRM.) This is another proof that a DRM-encumbered product doesn't belong to the person who bought it. Microsoft said it will refund customers, but this is no excuse for selling them restricted books.

DRM in Windows, introduced to cater to Bluray disks. (The article talks about how the same malware would later be introduced in MacOS. That had not been done at the time, but it was done subsequently.)

Insecurity

These bugs are/were not intentional, so unlike the rest of the file they do not count as malware. We mention them to refute the supposition that prestigious proprietary software doesn't have grave bugs.

Exploits of bugs in Windows, which were developed by the NSA and then leaked by the Shadowbrokers group, are now being used to attack a great number of Windows computers with ransomware.

A flaw in Internet Explorer and Edge allows an attacker to retrieve Microsoft account credentials, if the user is tricked into visiting a malicious link.

Point-of-sale terminals running Windows were taken over and turned into a botnet for the purpose of collecting customers' credit card numbers.

Interference

This section gives examples of Microsoft software harassing or annoying the user, or causing trouble for the user. These actions are like sabotage but the word “sabotage” is too strong for them.

Sabotage

The wrongs in this section are not precisely malware, since they do not involve making the program that runs in a way that hurts the user. But they are a lot like malware, since they are technical Microsoft actions that harm the users of specific Microsoft software.

Subscriptions

Microsoft Office forces users to subscribe to Office 365 to be able to create/edit documents.

Surveillance

Tethers

Tethers are functionalities that require constant (or very frequent) connection to a server.

The recent versions of Microsoft Office require the user to connect to Microsoft servers at least every thirty-one days. Otherwise, the software will refuse to edit any documents or create new ones. It will be restricted to viewing and printing.

Jails

Jails are systems that impose censorship on application programs.

Tyrants

Tyrants are systems that reject any operating system not “authorized” by the manufacturer.

Microsoft accidentally left a way for users to install GNU/Linux on Windows RT tablets, but now it has “fixed” the “error”. They have the gall to call this “protecting” the users. The article talks of installing “Linux”, but the context shows it is really GNU/Linux that users install.

Mobile devices that come with Windows 8 are tyrants.

As this page shows, if you do want to clean your computer of malware, the first software to delete is Windows.