You need the AcrobatUpd11023.msp file. While it was previously on Adobe's FTP sites, it may now be found in community archives or through specialized enterprise update sites.
Disclaimer: This guide is for informational purposes for users managing legacy software systems. Always ensure software is acquired through authorized channels. If you'd like, I can: Provide a link to a to Acrobat XI. FULL Adobe Acrobat XI Pro 11.0.23 Patch