htxxtp://www.techsupportalert.com/content/best-free-pdf-tools.htm#PDFill-PDF-Tools
The installer contains OpenCandy but you can download a portable zip file here without bundling such advertising program.
Installer filled with other unwanted preselected programs and toobars...
But still open-source with clean/safe installers on their Github page : https://github.com/torakiki/pdfsam-v2/releases/
Infected with: Adware:Win32/OpenCandy
Don't download the program directly from this site, it is bundled with adware. The adware free download is only available from sourceforge: http://sourceforge.net/projects/pdfsam/files/
See confirmation of this via: http://www.pdfsam.org/freeandopen/