Adobe no longer offers downloads or activation servers for Acrobat 9. The activation servers for Creative Suite 4 (which included Acrobat 9) were shut down in 2021.
Searching for a "free download" of the full version of presents significant security and legal risks, as the software is no longer officially distributed for free by Adobe. Acrobat 9 Pro reached its end of support on June 26, 2013 . Security and Technical Risks --- Adobe Acrobat 9 Pro Free Download Full Version