Proprietary Software Is Often Malware

Proprietary software, also called nonfree software, means software that doesn't respect users' freedom and community. A proprietary program puts its developer or owner in a position of power over its users. This power is in itself an injustice.

The point of this directory is to show by examples that the initial injustice of proprietary software often leads to further injustices: malicious functionalities.

Power corrupts; the proprietary program's developer is tempted to design the program to mistreat its users. (Software designed to function in a way that mistreats the user is called malware.) Of course, the developer usually does not do this out of malice, but rather to profit more at the users' expense. That does not make it any less nasty or more legitimate.

Yielding to that temptation has become ever more frequent; nowadays it is standard practice. Modern proprietary software is typically an opportunity to be tricked, harmed, bullied or swindled.

Online services are not released software, but in regard to all the bad aspects, using a service is equivalent to using a copy of released software. In particular, a service can be designed to mistreat the user, and many services do that. However, we do not list instances of malicious dis-services here, for two reasons. First, a service (whether malicious or not) is not a program that one could install a copy of, and there is no way at all for users to change it. Second, it is so obvious that a service can mistreat users if the owner wishes that we hardly need to prove it.

However, most online services require the user to run a nonfree app. The app is released software, so we do list malicious functionalities of these apps. Mistreatment by the service itself is imposed by use of the app, so sometimes we mention those mistreatments too—but we try to state explicitly what is done by the app and what is done by the dis-service.

When a web site provides access to a service, it very likely sends nonfree JavaScript software to execute in the user's browser. Such JavaScript code is released software, and it's morally equivalent to other nonfree apps. If it does malicious things, we want to mention them here.

When talking about mobile phones, we do list one other malicious characteristic, location tracking which is caused by the underlying radio system rather than by the specific software in them.

As of September, 2022, the pages in this directory list around 550 instances of malicious functionalities (with more than 670 references to back them up), but there are surely thousands more we don't know about.

Ideally we would list every instance. If you come across an instance which we do not list, please write to to tell us about it. Please include a reference to a reputable article that describes the malicious behavior clearly; we won't list an item without documentation to point to.

If you want to be notified when we add new items or make other changes, subscribe to the mailing list <>.

Injustices or techniques Products or companies
  1. Back door:  any feature of a program that enables someone who is not supposed to be in control of the computer where it is installed to send it commands.
  2. Digital restrictions management, or “DRM”:  functionalities designed to restrict what users can do with the data in their computers.
  3. Jail:  system that imposes censorship on application programs.
  4. Tether:  functionality that requires permanent (or very frequent) connection to a server.
  5. Tyrant:  system that rejects any operating system not “authorized” by the manufacturer.

Users of proprietary software are defenseless against these forms of mistreatment. The way to avoid them is by insisting on free (freedom-respecting) software. Since free software is controlled by its users, they have a pretty good defense against malicious software functionality.

Latest additions


UEFI makes computers vulnerable to advanced persistent threats that are almost impossible to detect once installed...

  • 2022-10

    The Microsoft Office encryption is weak, and susceptible to attack.

    Encryption is a tricky field, and easy to mess up. It is wise to insist on encryption software that is (1) free software and (2) studied by experts.

  • 2022-11

    Obeying a demand by the Chinese government, Apple restricted the use of AirDrop in China. It imposed a ten-minute time limit during which users can receive files from non contacts. This makes it nearly impossible to use AirDrop for its intended purpose, which is to exchange files with strangers between iMonsters in physical proximity. This happened after it became known that dissenters were using the app to distribute digital anti-government fliers anonymously.

  • 2022-10

    Xiaomi provides a tool to unlock the bootloader of Xiaomi smartphones and tablets, but this requires creating an account on the company's servers, i.e. providing your phone number. This is the price you have to pay for “legally” running a free software operating system on Xiaomi devices. But the manufacturer retains control of the unlocked device through a backdoor in the bootloader—the same backdoor that was remotely used to unlock it.

  • 2022-09

    B-CAS [1] is the digital restrictions management (DRM) system used by Japanese TV broadcasters, including state-run TV. It is sold by the B-CAS company, which has a de-facto monopoly on it. Initially intended for pay-TV, its use was extended to digital free-to-air broadcasting as a means to enforce restrictions on copyrighted works. The system encrypts works that permit free redistribution just like other works, thus denying users their nominal rights.

    On the client side, B-CAS is typically implemented by a card that plugs into a compatible receiver, or alternatively by a tuner card that plugs into a computer. Beside implementing drastic copying and viewing restrictions, this system gives broadcasters full power over users, through back doors among other means. For example:

    • It can force messages to the user's TV screen, and the user can't turn them off.
    • It can collect viewing information and share it with other companies to take surveys. Until 2011, user registration was required, so the viewing habits of each customer were recorded. We don't know whether this personal information was deleted from the company's servers after 2011.
    • Each card has an ID, which enables broadcasters to force customer-specific updates via the back door normally used to update the decryption key. Thus pay-TV broadcasters can disable decryption of the broadcast wave if subscription fees are not paid on time. This feature could also be used by any broadcaster (possibly instructed by the government) to stop certain persons from watching TV.
    • Since the software in receivers is nonfree, and tuner cards are designed for either Windows or MacOS, it is impossible to legally watch Japanese TV from the Free World.
    • As the export of B-CAS cards is illegal, people outside Japan can't (officially) decrypt the satellite broadcast signal that may spill over to their location. They are thus deprived of a valuable source of information about what happens in Japan.

    These unacceptable restrictions led to a sort of cat-and-mouse game, with some users doing their best to bypass the system, and broadcasters trying to stop them without much success: cryptographic keys were retrieved through the back door of the B-CAS card, illegal cards were made and sold on the black market, as well as a tuner for PC that disables the copy control signal.

    While B-CAS cards are still in use with older equipment, modern high definition TVs have an even nastier version of this DRM (called ACAS) in a special chip that is built into the receiver. The chip can update its own software from the company's servers, even when the receiver is turned off (but still plugged into an outlet). This feature could be abused to disable stored TV programs that the power in place doesn't agree with, thus interfering with free speech.

    Being part of the receiver, the ACAS chip is supposed to be tamper-resistant. Time will tell…

    [1] We thank the free software supporter who translated this article from Japanese, and shared his experience of B-CAS with us. (Unfortunately, the article presents DRM as a good thing.)

  • 2022-08

    A security researcher found that the iOS in-app browser of TikTok injects keylogger-like JavaScript code into outside web pages. This code has the ability to track all users' activities, and to retrieve any personal data that is entered on the pages. We have no way of verifying TikTok's claim that the keylogger-like code only serves purely technical functions. Some of the accessed data could well be saved to the company's servers, and even shared with third parties. This would open the door to extensive surveillance, including by the Chinese government (to which TikTok has indirect ties). There is also a risk that the data would be stolen by crackers, and used to launch malware attacks.

    The iOS in-app browsers of Instagram and Facebook behave essentially the same way as TikTok's. The main difference is that Instagram and Facebook allow users to access third-party sites with their default browser, whereas TikTok makes it nearly impossible.

    The researcher didn't study the Android versions of in-app browsers, but we have no reason to assume they are safer than the iOS versions.

    Please note that the article wrongly refers to crackers as “hackers.”

More items…