I might be able to shed some light on this as I have done research on "dark patterns."
From the Wikipedia entry on "Dark Patterns":
Misdirection
Common in software installers, misdirection presents the user with a button in the fashion of a typical continuation button. A dark pattern would show a prominent "I accept these terms" button asking the user to accept the terms of a program unrelated to the one they are trying to install. Since the user typically will accept the terms by force of habit, the unrelated program can subsequently be installed. The installer's authors do this because the authors of the unrelated program pay for each installation that they procure. The alternative route in the installer, allowing the user to skip installing the unrelated program, is much less prominently displayed, or seems counter-intuitive (such as declining the terms of service).
This 2016 article provides insight into MalwareBytes rationale for blocking of dark pattern installers from Sourceforge:
https://blog.malwarebytes.com/cybercrim ... s-ask-why/
A dark pattern installer works like a trojan horse, except that they skirt the issue of legality by giving the user some means of opting out, but that opt-out is counter-intuitively placed, designed, and worded to maximize the number of users who inadvertently permit the installations. That lets the software distributor blame the victim 'the second time you clicked 'I agree,' you were giving it permission to install Adaware Web Companion" -- described by safetydetectives.com as software that "adds an annoying toolbar to your browser, slows down your PC, and changes your web browser’s home page." I'm not here to debate their characterization, but a search for that program on Google provided results that were overwhelmingly about how to remove it and people questioning how it got on their computer.
- Adaware.png (45.66 KiB) Viewed 3034 times
So how did you end up with an installer that contained that? More dark patterns, this time on the web page for downloads:
- fzdownload.png (98.14 KiB) Viewed 3034 times
This is a classic example of a dark pattern web interface. There's one button on the page -- a huge, green one that says "Download FileZilla Client." It's only if you read the relatively small font notice below the button that you see "This installer may contain bundled offers." What that really means is "This installer uses dark patterns to trick users into installing as-of-now unspecified, and probably unwanted, software." At the bottom is a vaguely worded text link that says "Show additional download options." Like what? Bittorrent? FTP? Nope. That link means "Show me how to download what I came here for, without any additional third-party software."
Legislators and regulatory agencies in the EU and US have been chipping away at "dark patterns," invalidating agreements obtained through dark pattern interface design techniques. But the efforts are still in their infancy and far from universal.