If this is a business-related file, you can check the SEC EDGAR database for official corporate reports using "Capital Island" as a search term.
No public files or specific documents under the name were found in verified government databases or official repositories. File: Capital.Island.zip ...
If you have a link to the specific page where you saw this file, providing it will help in retrieving the text. Otherwise, knowing the source would allow for a more targeted search. If this is a business-related file, you can