Hosting the program packages on gimp.org would undoubtedly solve the problem. Has anyone submitted a bug report to the devs yet about this?

GIMP.ORG NEWS November 5, 2013

In the past few months, we have received some complaints about the site where the GIMP installers for the Microsoft Windows platforms are hosted.

SourceForge, once a useful and trustworthy place to develop and host FLOSS applications, has faced a problem with the ads they allow on their sites - the green "Download here" buttons that appear on many, many adds leading to all kinds of unwanted utilities have been spotted there as well.

The tipping point was the introduction of their own SourceForge Installer software, which bundles third-party offers with Free Software packages. We do not want to support this kind of behavior, and have thus decided to abandon SourceForge.

From now on, Jernej Simončič, who provides the installer packages, uploads them to our FTP directly, and from there they will be distributed automatically to our mirrors. Please check Downloads page for updated information. Because of malware being found in SourceForge downloads, this link has been removed.
will remain active for the time being and direct users to the new download locations.

Excellent.